| 3 Months | 1 Year | 3 Years | 5 Years | ||||||||||
| N | % | Std. Err. | N | % | Std. Err. | N | % | Std. Err. | N | % | Std. Err. | ||
| Total | All | 4,325 | 90.1% | 0.5% | 4,325 | 85.3% | 0.5% | 4,431 | 77.2% | 0.6% | 4,564 | 70.6% | 0.7% |
| Yearly Center Volume | 0-5 | 180 | 86.0% | 2.6% | 180 | 80.9% | 2.9% | 194 | 77.0% | 3.1% | 180 | 60.3% | 3.8% |
| 6-10 | 439 | 87.1% | 1.6% | 439 | 82.3% | 1.8% | 352 | 78.1% | 2.2% | 367 | 72.5% | 2.4% | |
| 11-16 | 773 | 90.0% | 1.1% | 773 | 84.5% | 1.3% | 817 | 72.6% | 1.6% | 844 | 72.4% | 1.6% | |
| 17-24 | 824 | 89.4% | 1.1% | 824 | 85.0% | 1.3% | 748 | 79.3% | 1.5% | 1,057 | 68.6% | 1.4% | |
| 25+ | 2,109 | 91.4% | 0.6% | 2,109 | 86.8% | 0.7% | 2,320 | 78.1% | 0.9% | 2,116 | 71.5% | 1.0% | |