| Region 5 | |||||||||||||
| Population | |||||||||||||
| Source: Population Estimates Program, Population Division, U.S. Census Bureau WA | |||||||||||||
| 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | |
| Blaine | 16,938 | 17,169 | 17,203 | 17,326 | 18,991 | 19,798 | 20,378 | 20,791 | 21,103 | 21,166 | 21,501 | 21,560 | 21,731 |
| Camas | 874 | 836 | 841 | 865 | 991 | 1,002 | 1,037 | 1,049 | 1,013 | 1,050 | 1,088 | 1,102 | 1,126 |
| Cassia | 21,322 | 21,443 | 21,324 | 21,573 | 21,416 | 21,577 | 21,720 | 21,610 | 21,393 | 21,324 | 21,365 | 20,960 | 21,348 |
| Gooding | 13,523 | 13,571 | 13,658 | 13,743 | 14,155 | 14,207 | 14,307 | 14,329 | 14,346 | 14,461 | 14,404 | 14,250 | 14,295 |
| Jerome | 17,329 | 17,535 | 17,957 | 18,110 | 18,342 | 18,449 | 18,703 | 18,913 | 19,279 | 19,638 | 20,130 | 20,066 | 20,468 |
| Lincoln | 3,757 | 3,795 | 3,778 | 3,839 | 4,044 | 4,132 | 4,207 | 4,321 | 4,326 | 4,545 | 4,522 | 4,497 | 4,503 |
| Minidoka | 20,565 | 20,506 | 20,205 | 20,284 | 20,174 | 19,677 | 19,465 | 19,349 | 19,229 | 19,014 | 19,041 | 18,564 | 18,645 |
| Twin Falls | 60,402 | 61,510 | 62,222 | 62,970 | 64,284 | 64,731 | 65,472 | 67,082 | 67,935 | 69,419 | 71,575 | 73,058 | 74,284 |
| Total | 154,710 | 156,365 | 157,188 | 158,710 | 162,397 | 163,573 | 165,289 | 167,444 | 168,624 | 170,617 | 173,626 | 174,057 | 176,400 |