| Residency | Year | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 1999 | 2000 | 2001 | 2002 | 2003 | 2004 | 2005 | 2006 | 2007 | 2008 | |
| Total | 4,226 | 4,610 | 5,355 | 6,034 | 8,038 | 11,851 | 15,399 | 19,216 | 22,924 | 25,465 |
| U.S. Resident | 4,143 | 4,521 | 5,267 | 5,918 | 7,900 | 11,654 | 15,164 | 18,963 | 22,673 | 25,207 |
| Nonresident Alien | 36 | 43 | 47 | 81 | 108 | 171 | 212 | 232 | 228 | 240 |
| Unknown | 47 | 46 | 41 | 35 | 30 | 26 | 23 | 21 | 23 | 18 |
| Total (%) | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% |
| U.S. Resident | 98.0% | 98.1% | 98.4% | 98.1% | 98.3% | 98.3% | 98.5% | 98.7% | 98.9% | 99.0% |
| Nonresident Alien | 0.9% | 0.9% | 0.9% | 1.3% | 1.3% | 1.4% | 1.4% | 1.2% | 1.0% | 0.9% |
| Unknown | 1.1% | 1.0% | 0.8% | 0.6% | 0.4% | 0.2% | 0.1% | 0.1% | 0.1% | 0.1% |