| Residency | Year | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | |
| Total | 2,414 | 2,525 | 2,478 | 2,421 | 2,257 | 2,055 | 1,808 | 1,588 | 1,332 | 1,327 |
| U.S. Resident | 2,396 | 2,507 | 2,459 | 2,407 | 2,248 | 2,047 | 1,807 | 1,582 | 1,322 | 1,321 |
| Nonresident Alien | 9 | 7 | 7 | 7 | 9 | 8 | 1 | 6 | 9 | 5 |
| Unknown | 9 | 11 | 12 | 7 | - | - | - | - | 1 | 1 |
| Total (%) | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% |
| U.S. Resident | 99.3% | 99.3% | 99.2% | 99.4% | 99.6% | 99.6% | 99.9% | 99.6% | 99.2% | 99.5% |
| Nonresident Alien | 0.4% | 0.3% | 0.3% | 0.3% | 0.4% | 0.4% | 0.1% | 0.4% | 0.7% | 0.4% |
| Unknown | 0.4% | 0.4% | 0.5% | 0.3% | - | - | - | - | 0.1% | 0.1% |