| Residency | Year | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | |
| Total | 778 | 874 | 1,029 | 1,254 | 1,421 | 1,482 | 1,654 | 2,059 | 1,791 | 1,212 |
| U.S. Resident | 769 | 863 | 1,017 | 1,240 | 1,402 | 1,466 | 1,640 | 2,047 | 1,779 | 1,207 |
| Nonresident Alien | 5 | 7 | 7 | 9 | 14 | 11 | 10 | 10 | 10 | 5 |
| Unknown | 4 | 4 | 5 | 5 | 5 | 5 | 4 | 2 | 2 | - |
| Total (%) | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% |
| U.S. Resident | 98.8% | 98.7% | 98.8% | 98.9% | 98.7% | 98.9% | 99.2% | 99.4% | 99.3% | 99.6% |
| Nonresident Alien | 0.6% | 0.8% | 0.7% | 0.7% | 1.0% | 0.7% | 0.6% | 0.5% | 0.6% | 0.4% |
| Unknown | 0.5% | 0.5% | 0.5% | 0.4% | 0.4% | 0.3% | 0.2% | 0.1% | 0.1% | - |