The latest officially reported population of Chad was 20,299,123 in 2024 vs 12,277,109 people in Tunisia in 2024. In 2026, based on the adjusted UN estimation, the current Chad's population is 21,893,857 people compared to 12,437,803 in Tunisia.
Population statistics:
- Chad's population is 1.76 times bigger than Tunisia's.
- Chad is ranked the 64th most populous country in the world, while Tunisia is the 81st.
- The countries together account for 0.41% of the world: 0.26% for Chad vs 0.15% for Tunisia.
- For the last 10 years, Chad has had an average growth rate of +3.65% per year vs +0.89% in Tunisia.
- Since 2006, the population of Chad has increased from 10.7M people to 21.9M (104.5% growth), while Tunisia has grown from 10.3M to 12.4M (20.2% growth).
Chad vs Tunisia: population by year and forecast
| Year | Population | |
|---|---|---|
Chad
|
Tunisia
|
|
| 2100 | 70,884,357 | 10,722,837 |
| 2099 | 70,557,567 | 10,798,417 |
| 2098 | 70,230,207 | 10,872,527 |
| 2097 | 69,842,152 | 10,944,510 |
| 2096 | 69,451,196 | 11,017,262 |
| 2095 | 69,060,721 | 11,088,773 |
| 2094 | 68,666,177 | 11,159,761 |
| 2093 | 68,236,720 | 11,228,741 |
| 2092 | 67,782,173 | 11,296,441 |
| 2091 | 67,325,804 | 11,362,922 |
| 2090 | 66,831,262 | 11,428,150 |
| 2089 | 66,335,362 | 11,492,395 |
| 2088 | 65,849,776 | 11,554,451 |
| 2087 | 65,329,155 | 11,616,399 |
| 2086 | 64,802,341 | 11,677,706 |
| 2085 | 64,247,517 | 11,736,824 |
| 2084 | 63,683,201 | 11,795,185 |
| 2083 | 63,107,011 | 11,853,617 |
| 2082 | 62,546,281 | 11,911,196 |
| 2081 | 61,935,077 | 11,966,771 |
| 2080 | 61,322,770 | 12,023,486 |
| 2079 | 60,689,500 | 12,080,879 |
| 2078 | 60,041,413 | 12,138,513 |
| 2077 | 59,398,544 | 12,194,072 |
| 2076 | 58,750,589 | 12,247,445 |
| 2075 | 58,088,399 | 12,301,960 |
| 2074 | 57,429,638 | 12,355,470 |
| 2073 | 56,751,288 | 12,410,281 |
| 2072 | 56,050,641 | 12,463,568 |
| 2071 | 55,351,270 | 12,517,952 |
| 2070 | 54,656,129 | 12,571,557 |
| 2069 | 53,956,737 | 12,625,027 |
| 2068 | 53,248,745 | 12,677,388 |
| 2067 | 52,550,963 | 12,728,611 |
| 2066 | 51,808,021 | 12,778,160 |
| 2065 | 51,071,215 | 12,827,417 |
| 2064 | 50,307,695 | 12,873,288 |
| 2063 | 49,556,347 | 12,917,720 |
| 2062 | 48,797,884 | 12,960,075 |
| 2061 | 48,036,580 | 12,999,502 |
| 2060 | 47,241,459 | 13,037,172 |
| 2059 | 46,442,418 | 13,069,268 |
| 2058 | 45,655,034 | 13,098,461 |
| 2057 | 44,870,896 | 13,124,682 |
| 2056 | 44,078,534 | 13,147,057 |
| 2055 | 43,275,519 | 13,164,337 |
| 2054 | 42,486,590 | 13,177,456 |
| 2053 | 41,688,608 | 13,184,564 |
| 2052 | 40,889,772 | 13,188,052 |
| 2051 | 40,092,484 | 13,187,435 |
| 2050 | 39,299,495 | 13,181,992 |
| 2049 | 38,521,793 | 13,173,401 |
| 2048 | 37,723,298 | 13,160,968 |
| 2047 | 36,947,445 | 13,144,429 |
| 2046 | 36,172,851 | 13,125,908 |
| 2045 | 35,391,232 | 13,104,999 |
| 2044 | 34,632,170 | 13,081,801 |
| 2043 | 33,864,845 | 13,057,259 |
| 2042 | 33,104,772 | 13,031,516 |
| 2041 | 32,347,709 | 13,006,019 |
| 2040 | 31,617,805 | 12,979,703 |
| 2039 | 30,871,258 | 12,952,741 |
| 2038 | 30,129,880 | 12,925,306 |
| 2037 | 29,393,074 | 12,896,316 |
| 2036 | 28,653,774 | 12,865,989 |
| 2035 | 27,935,849 | 12,835,689 |
| 2034 | 27,223,833 | 12,803,284 |
| 2033 | 26,506,530 | 12,766,519 |
| 2032 | 25,790,343 | 12,728,299 |
| 2031 | 25,078,386 | 12,687,827 |
| 2030 | 24,381,060 | 12,644,489 |
| 2029 | 23,686,105 | 12,596,686 |
| 2028 | 22,995,214 | 12,542,752 |
| 2027 | 22,312,346 | 12,484,560 |
| 2026 | 21,738,687 | 12,420,467 |
| 2025 | 21,174,977 | 12,351,028 |
| 2024 | 20,299,123 | 12,277,109 |
| 2023 | 19,319,064 | 12,200,431 |
| 2022 | 18,455,316 | 12,119,334 |
| 2021 | 17,828,273 | 12,048,622 |
| 2020 | 17,224,679 | 11,974,057 |
| 2019 | 16,685,223 | 11,875,081 |
| 2018 | 16,156,531 | 11,765,514 |
| 2017 | 15,622,759 | 11,650,498 |
| 2016 | 15,114,655 | 11,528,674 |
| 2015 | 14,647,621 | 11,402,264 |
| 2014 | 14,188,678 | 11,274,288 |
| 2013 | 13,691,079 | 11,141,361 |
| 2012 | 13,210,998 | 11,009,647 |
| 2011 | 12,754,997 | 10,886,035 |
| 2010 | 12,312,575 | 10,765,980 |
| 2009 | 11,893,754 | 10,650,681 |
| 2008 | 11,476,296 | 10,542,635 |
| 2007 | 11,081,660 | 10,441,702 |
| 2006 | 10,706,424 | 10,346,410 |
| 2005 | 10,328,092 | 10,255,472 |
| 2004 | 9,920,036 | 10,166,163 |
| 2003 | 9,487,833 | 10,071,632 |
| 2002 | 9,116,192 | 9,971,515 |
| 2001 | 8,804,124 | 9,869,677 |
| 2000 | 8,512,093 | 9,764,935 |
| 1999 | 8,222,705 | 9,655,963 |
| 1998 | 7,938,840 | 9,541,667 |
| 1997 | 7,670,366 | 9,421,270 |
| 1996 | 7,410,108 | 9,294,432 |
| 1995 | 7,089,064 | 9,161,258 |
| 1994 | 6,783,450 | 9,018,448 |
| 1993 | 6,629,146 | 8,857,910 |
| 1992 | 6,474,656 | 8,682,512 |
| 1991 | 6,205,676 | 8,501,827 |
| 1990 | 5,982,833 | 8,324,509 |
| 1989 | 5,819,586 | 8,151,660 |
| 1988 | 5,625,602 | 7,974,440 |
| 1987 | 5,438,309 | 7,789,987 |
| 1986 | 5,251,069 | 7,600,301 |
| 1985 | 5,096,269 | 7,409,903 |
| 1984 | 5,045,145 | 7,220,044 |
| 1983 | 4,979,130 | 7,053,800 |
| 1982 | 4,738,483 | 6,908,642 |
| 1981 | 4,520,959 | 6,758,284 |
| 1980 | 4,515,453 | 6,606,195 |
| 1979 | 4,505,384 | 6,456,419 |
| 1978 | 4,411,366 | 6,309,390 |
| 1977 | 4,331,667 | 6,155,931 |
| 1976 | 4,251,297 | 5,996,994 |
| 1975 | 4,167,234 | 5,839,262 |
| 1974 | 4,078,356 | 5,684,674 |
| 1973 | 3,985,909 | 5,537,242 |
| 1972 | 3,893,252 | 5,396,557 |
| 1971 | 3,807,316 | 5,261,658 |
| 1970 | 3,727,828 | 5,131,396 |
| 1969 | 3,651,113 | 5,004,697 |
| 1968 | 3,578,231 | 4,879,899 |
| 1967 | 3,508,512 | 4,760,970 |
| 1966 | 3,440,903 | 4,652,287 |
| 1965 | 3,374,220 | 4,561,385 |
| 1964 | 3,307,479 | 4,489,869 |
| 1963 | 3,240,905 | 4,427,131 |
| 1962 | 3,175,598 | 4,369,136 |
| 1961 | 3,111,947 | 4,316,278 |
| 1960 | 3,049,838 | 4,267,288 |
Data sources: United Nations | World Population Prospects (2025–2100, retrieved 2026-03-10); World Bank | Health (1960–2024, retrieved 2026-04-06).
GeoRank.org/population/chad/tunisia | CC BY 
From 2006 to 2016, the population of Chad increased by 4,408,231 people (a 41.2% growth), while Tunisia gained 1,182,264 people (a 11.4% growth).
For the next 10 years, from 2016 to 2026, Chad gained 6,779,202 people (a 44.9% growth), while Tunisia's population increased by 909,129 people (a 7.89% growth).
Chad was ranked 76th most populous country in 2006 and is 64th in 2026. Tunisia was ranked 79th in 2006 and ranked 81st now.
The UN's World Population Prospects forecasts that in 24 years (in 2050) Chad's population will grow by 79.5% to 39,299,495 people with a rank change from 64th to 52nd. The population of Tunisia will increase by 5.98% to 13,181,992 people and rank change from 81st to 89th.
Chad is projected to reach its peak in 2100 at 70.9M people compared to the peak of 13.2M people in 2052 for Tunisia.
Population growth rate by year
| Year | Growth rate | |
|---|---|---|
|
Chad
|
Tunisia
|
|
| 2100 | 0.46% | -0.7% |
| 2099 | 0.47% | -0.68% |
| 2098 | 0.56% | -0.66% |
| 2097 | 0.56% | -0.66% |
| 2096 | 0.57% | -0.64% |
| 2095 | 0.57% | -0.64% |
| 2094 | 0.63% | -0.61% |
| 2093 | 0.67% | -0.6% |
| 2092 | 0.68% | -0.59% |
| 2091 | 0.74% | -0.57% |
| 2090 | 0.75% | -0.56% |
| 2089 | 0.74% | -0.54% |
| 2088 | 0.8% | -0.53% |
| 2087 | 0.81% | -0.52% |
| 2086 | 0.86% | -0.5% |
| 2085 | 0.89% | -0.49% |
| 2084 | 0.91% | -0.49% |
| 2083 | 0.9% | -0.48% |
| 2082 | 0.99% | -0.46% |
| 2081 | 1% | -0.47% |
| 2080 | 1.04% | -0.48% |
| 2079 | 1.08% | -0.47% |
| 2078 | 1.08% | -0.46% |
| 2077 | 1.1% | -0.44% |
| 2076 | 1.14% | -0.44% |
| 2075 | 1.15% | -0.43% |
| 2074 | 1.2% | -0.44% |
| 2073 | 1.25% | -0.43% |
| 2072 | 1.26% | -0.43% |
| 2071 | 1.27% | -0.43% |
| 2070 | 1.3% | -0.42% |
| 2069 | 1.33% | -0.41% |
| 2068 | 1.33% | -0.4% |
| 2067 | 1.43% | -0.39% |
| 2066 | 1.44% | -0.38% |
| 2065 | 1.52% | -0.36% |
| 2064 | 1.52% | -0.34% |
| 2063 | 1.55% | -0.33% |
| 2062 | 1.58% | -0.3% |
| 2061 | 1.68% | -0.29% |
| 2060 | 1.72% | -0.25% |
| 2059 | 1.72% | -0.22% |
| 2058 | 1.75% | -0.2% |
| 2057 | 1.8% | -0.17% |
| 2056 | 1.86% | -0.13% |
| 2055 | 1.86% | -0.1% |
| 2054 | 1.91% | -0.05% |
| 2053 | 1.95% | -0.03% |
| 2052 | 1.99% | 0.005% |
| 2051 | 2.02% | 0.04% |
| 2050 | 2.02% | 0.07% |
| 2049 | 2.12% | 0.09% |
| 2048 | 2.1% | 0.13% |
| 2047 | 2.14% | 0.14% |
| 2046 | 2.21% | 0.16% |
| 2045 | 2.19% | 0.18% |
| 2044 | 2.27% | 0.19% |
| 2043 | 2.3% | 0.2% |
| 2042 | 2.34% | 0.2% |
| 2041 | 2.31% | 0.2% |
| 2040 | 2.42% | 0.21% |
| 2039 | 2.46% | 0.21% |
| 2038 | 2.51% | 0.22% |
| 2037 | 2.58% | 0.24% |
| 2036 | 2.57% | 0.24% |
| 2035 | 2.62% | 0.25% |
| 2034 | 2.71% | 0.29% |
| 2033 | 2.78% | 0.3% |
| 2032 | 2.84% | 0.32% |
| 2031 | 2.86% | 0.34% |
| 2030 | 2.93% | 0.38% |
| 2029 | 3% | 0.43% |
| 2028 | 3.06% | 0.47% |
| 2027 | 2.64% | 0.52% |
| 2026 | 2.66% | 0.56% |
| 2025 | 4.31% | 0.6% |
| 2024 | 5.07% | 0.63% |
| 2023 | 4.68% | 0.67% |
| 2022 | 3.52% | 0.59% |
| 2021 | 3.5% | 0.62% |
| 2020 | 3.23% | 0.83% |
| 2019 | 3.27% | 0.93% |
| 2018 | 3.42% | 0.99% |
| 2017 | 3.36% | 1.06% |
| 2016 | 3.19% | 1.11% |
| 2015 | 3.23% | 1.14% |
| 2014 | 3.63% | 1.19% |
| 2013 | 3.63% | 1.2% |
| 2012 | 3.58% | 1.14% |
| 2011 | 3.59% | 1.12% |
| 2010 | 3.52% | 1.08% |
| 2009 | 3.64% | 1.02% |
| 2008 | 3.56% | 0.97% |
| 2007 | 3.5% | 0.92% |
| 2006 | 3.66% | 0.89% |
| 2005 | 4.11% | 0.88% |
| 2004 | 4.56% | 0.94% |
| 2003 | 4.08% | 1% |
| 2002 | 3.54% | 1.03% |
| 2001 | 3.43% | 1.07% |
| 2000 | 3.52% | 1.13% |
| 1999 | 3.58% | 1.2% |
| 1998 | 3.5% | 1.28% |
| 1997 | 3.51% | 1.36% |
| 1996 | 4.53% | 1.45% |
| 1995 | 4.51% | 1.58% |
| 1994 | 2.33% | 1.81% |
| 1993 | 2.39% | 2.02% |
| 1992 | 4.33% | 2.13% |
| 1991 | 3.72% | 2.13% |
| 1990 | 2.81% | 2.12% |
| 1989 | 3.45% | 2.22% |
| 1988 | 3.44% | 2.37% |
| 1987 | 3.57% | 2.5% |
| 1986 | 3.04% | 2.57% |
| 1985 | 1.01% | 2.63% |
| 1984 | 1.33% | 2.36% |
| 1983 | 5.08% | 2.1% |
| 1982 | 4.81% | 2.22% |
| 1981 | 0.12% | 2.3% |
| 1980 | 0.22% | 2.32% |
| 1979 | 2.13% | 2.33% |
| 1978 | 1.84% | 2.49% |
| 1977 | 1.89% | 2.65% |
| 1976 | 2.02% | 2.7% |
| 1975 | 2.18% | 2.72% |
| 1974 | 2.32% | 2.66% |
| 1973 | 2.38% | 2.61% |
| 1972 | 2.26% | 2.56% |
| 1971 | 2.13% | 2.54% |
| 1970 | 2.1% | 2.53% |
| 1969 | 2.04% | 2.56% |
| 1968 | 1.99% | 2.5% |
| 1967 | 1.96% | 2.34% |
| 1966 | 1.98% | 1.99% |
| 1965 | 2.02% | 1.59% |
| 1964 | 2.05% | 1.42% |
| 1963 | 2.06% | 1.33% |
| 1962 | 2.05% | 1.22% |
| 1961 | 2.04% | 1.15% |
Data sources: United Nations | World Population Prospects (2025–2100, retrieved 2026-03-10); World Bank | Health (1961–2024, retrieved 2026-04-06).
GeoRank.org/population/chad/tunisia | CC BY
In 2024, the population of Chad grew by 5.07%, while Tunisia's population grew by 0.63%.
Live population counters
|
Chad
|
Tunisia
|
|
|---|---|---|
| Current population |
21893857
|
12437803
|
| Population rank | 64/197 | 81/197 |
| Percent of world population | 0.26% | 0.15% |
| One net population change |
32.2 seconds
|
6.85 minutes
|
| One birth every |
38.5 seconds
|
3.13 minutes
|
| One death every |
2.47 minutes
|
7.1 minutes
|
| Daily growth/decline | +2,685 | +210 |
| Annual growth/decline | +980,059 | +76,678 |
| Annual growth/decline rate | +5.07% | +0.63% |
| Population growth rate rank | 2/197 | 124/197 |
| One migration net change every |
4.28 minutes
|
36.3 minutes
|
| Annual migration change | -123,104 | -14,523 |
| Net migration rank | 184/196 | 142/196 |
| Foreign-born residents | 1,269,673 | 63,201 |
| Foreign-born residents rank | 50/195 | 145/195 |
| Foreign-born share of population | 6.3% | 0.5% |
| Foreign-born share rank | 83/195 | 177/195 |
Natural population change vs migration
| Year | Population change | |||
|---|---|---|---|---|
|
Chad
|
Tunisia
|
|||
| Natural | Migration | Natural | Migration | |
| 2025 | - | -123,104 | - | -14,523 |
| 2024 | - | 204,040 | - | -15,221 |
| 2023 | 605,924 | 496,830 | 93,663 | -14,001 |
| 2022 | 588,060 | 36,670 | 96,531 | -14,001 |
| 2021 | 554,851 | 74,509 | 68,087 | -9,190 |
| 2020 | 541,234 | 36,605 | 109,431 | -19,188 |
| 2019 | 530,540 | -29,451 | 127,312 | -19,612 |
| 2018 | 509,642 | 46,661 | 132,445 | -21,012 |
| 2017 | 494,304 | 16,916 | 140,971 | -22,365 |
| 2016 | 483,442 | 21,540 | 148,870 | -23,827 |
| 2015 | 478,010 | -48,918 | 153,007 | -25,229 |
| 2014 | 467,957 | 20,842 | 154,762 | -26,586 |
| 2013 | 454,517 | 51,887 | 154,687 | -17,020 |
| 2012 | 444,246 | 9,514 | 151,812 | -26,059 |
| 2011 | 428,989 | 29,256 | 143,401 | -21,935 |
| 2010 | 416,177 | 10,427 | 132,809 | -14,168 |
| 2009 | 401,937 | 9,108 | 125,465 | -13,512 |
| 2008 | 387,439 | 36,446 | 121,873 | -17,742 |
| 2007 | 376,732 | -11,339 | 118,920 | -21,190 |
| 2006 | 362,027 | 23,052 | 116,945 | -24,098 |
| 2005 | 352,302 | 19,281 | 115,374 | -26,361 |
| 2004 | 334,136 | 110,387 | 113,322 | -23,735 |
| 2003 | 314,740 | 105,140 | 111,926 | -12,459 |
| 2002 | 302,995 | 20,400 | 109,099 | -8,334 |
| 2001 | 297,254 | 3,484 | 110,146 | -7,235 |
| 2000 | 287,173 | -3,845 | 112,501 | -5,937 |
| 1999 | 278,264 | 17,175 | 114,829 | -3,452 |
| 1998 | 270,055 | 2,232 | 121,332 | -4,111 |
| 1997 | 261,030 | 3,631 | 128,327 | -4,756 |
| 1996 | 254,589 | 1,259 | 135,615 | -5,506 |
| 1995 | 234,010 | 152,232 | 144,345 | -8,095 |
| 1994 | 223,996 | 986 | 153,647 | -4,271 |
| 1993 | 229,984 | -146,386 | 160,922 | 10,771 |
| 1992 | 219,348 | 6,013 | 163,978 | 15,124 |
| 1991 | 200,102 | 112,492 | 166,245 | 16,021 |
| 1990 | 191,959 | -58,884 | 168,180 | 4,183 |
| 1989 | 188,485 | 4,924 | 169,221 | 4,100 |
| 1988 | 178,489 | 16,085 | 177,176 | 3,934 |
| 1987 | 156,797 | 23,220 | 184,101 | 3,711 |
| 1986 | 152,360 | 42,093 | 188,107 | 3,464 |
| 1985 | 145,845 | -30,686 | 186,344 | 2,887 |
| 1984 | 151,511 | -164,489 | 182,386 | 8,109 |
| 1983 | 144,684 | 247 | 179,878 | -37,895 |
| 1982 | 119,121 | 217,242 | 177,898 | -29,559 |
| 1981 | 111,907 | -13,232 | 176,628 | -24,242 |
| 1980 | 122,468 | -210,126 | 171,094 | -19,321 |
| 1979 | 117,780 | -9,974 | 171,463 | -23,688 |
| 1978 | 115,084 | -34,856 | 173,255 | -26,968 |
| 1977 | 113,498 | -34,318 | 174,539 | -13,910 |
| 1976 | 111,324 | -29,755 | 172,744 | -15,499 |
| 1975 | 109,315 | -22,768 | 166,991 | -8,765 |
| 1974 | 106,898 | -15,686 | 160,200 | -9,254 |
| 1973 | 104,418 | -10,737 | 153,525 | -9,606 |
| 1972 | 101,142 | -9,526 | 147,239 | -9,790 |
| 1971 | 89,404 | -9,153 | 142,296 | -9,949 |
| 1970 | 87,660 | -8,931 | 138,235 | -10,054 |
| 1969 | 83,413 | -8,714 | 135,257 | -10,049 |
| 1968 | 79,465 | -8,396 | 134,246 | -9,848 |
| 1967 | 76,142 | -7,771 | 132,626 | -19,155 |
| 1966 | 73,123 | -6,283 | 131,274 | -27,393 |
| 1965 | 70,913 | -4,384 | 127,673 | -49,751 |
| 1964 | 69,483 | -2,518 | 124,711 | -59,602 |
| 1963 | 67,414 | -1,228 | 120,865 | -60,505 |
| 1962 | 65,312 | -890 | 116,887 | -61,260 |
| 1961 | 63,639 | -760 | 111,459 | -61,369 |
| 1960 | 62,003 | -672 | 109,234 | -61,334 |
Data sources: World Bank | Health (1960–2025, retrieved 2026-04-06).
GeoRank.org/population/chad/tunisia | CC BY
Over the last 10 years, 88.7% of the population change in Chad is from natural causes (a gain of 5,253,964 people) and 11.3% is from migration (a gain of 672,204 people). In Tunisia 86.3% is from natural causes (a gain of 1,225,079 people) and 13.7% is from migration (a loss of 195,011 people).
As of 2024, 1,269,673 residents or 6.3% of the population were not native-born in Chad, compared to 63,201 people or 0.5% in Tunisia.
Biggest cities by population
Compare countries by 7 more topics
Population differences between Chad and Tunisia
|
Chad
|
Tunisia
|
|
|---|---|---|
| Life expectancy | 55.6 years | 77.1 years |
| Average age | 21.2 years | 34.5 years |
| Median age | 16.8 years | 33.5 years |
| Male:Female ratio | 50.2:49.8 | 49.4:50.6 |
| Fertility rate | 6.12 births per woman | 1.83 births per woman |
| Population density | 44.7 ppl/mi² | 207.1 ppl/mi² |
Population map with other countries
Data sources: World Bank | Health (1960–2024, retrieved 2026-04-06); United Nations | World Population Prospects (1960–2026, retrieved 2026-03-10); U.S. Census Bureau (1960–2025, retrieved 2026-02-08); Central Intelligence Agency (CIA) (2000–2019, retrieved 2026-02-20).
GeoRank.org/population/chad/tunisia | CC BY
Help us show the world through your eyes
Share a photo of your city and help others discover what it looks like to live there. Your contribution makes our data come alive.
Data sources:
- World Bank | Health (1960–2025, retrieved 2026-04-06)
- United Nations | World Population Prospects (1960–2100, retrieved 2026-03-10)
- U.S. Census Bureau (1960–2025, retrieved 2026-02-08)
- Central Intelligence Agency (CIA) (2000–2019, retrieved 2026-02-20)
- Wikidata (2026, retrieved 2026-02-08)
Creative Commons Attribution (CC BY) — you’re free to copy, share, remix, adapt, and use even commercially as long as you give appropriate credit and clearly indicate if you made changes. Other sources may be subject to different license terms.