| Residency | Year | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | |
| Total | 236 | 342 | 464 | 487 | 536 | 421 | 331 | 290 | 233 | 226 |
| U.S. Resident | 234 | 341 | 462 | 486 | 536 | 421 | 331 | 290 | 231 | 226 |
| Nonresident Alien | 1 | - | - | - | - | - | - | - | 2 | - |
| Unknown | 1 | 1 | 2 | 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 | 99.2% | 99.7% | 99.6% | 99.8% | 100.0% | 100.0% | 100.0% | 100.0% | 99.1% | 100.0% |
| Nonresident Alien | 0.4% | - | - | - | - | - | - | - | 0.9% | - |
| Unknown | 0.4% | 0.3% | 0.4% | 0.2% | - | - | - | - | - | - |