| Residency | Year | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | |
| Total | 2,277 | 2,429 | 2,484 | 2,417 | 2,281 | 2,315 | 2,163 | 1,052 | 1,031 | 1,005 |
| U.S. Resident | 2,252 | 2,412 | 2,466 | 2,403 | 2,275 | 2,308 | 2,156 | 1,050 | 1,025 | 998 |
| Nonresident Alien | 16 | 14 | 16 | 13 | 5 | 6 | 7 | 2 | 6 | 6 |
| Unknown | 9 | 3 | 2 | 1 | 1 | 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 | 98.9% | 99.3% | 99.3% | 99.4% | 99.7% | 99.7% | 99.7% | 99.8% | 99.4% | 99.3% |
| Nonresident Alien | 0.7% | 0.6% | 0.6% | 0.5% | 0.2% | 0.3% | 0.3% | 0.2% | 0.6% | 0.6% |
| Unknown | 0.4% | 0.1% | 0.1% | 0.0% | 0.0% | 0.0% | - | - | - | 0.1% |