| 3 Months | 1 Year | 3 Years | 5 Years | ||||||||||
| N | % | Std. Err. | N | % | Std. Err. | N | % | Std. Err. | N | % | Std. Err. | ||
| Total | All | 1,769 | 97.0% | 0.4% | 1,769 | 94.7% | 0.5% | 1,821 | 90.6% | 0.7% | 1,794 | 85.3% | 0.8% |
| Yearly Center Volume | 0-3 | 206 | 95.1% | 1.5% | 206 | 92.7% | 1.8% | 140 | 93.6% | 2.1% | 143 | 86.7% | 2.8% |
| 4-6 | 238 | 96.2% | 1.2% | 238 | 92.4% | 1.7% | 215 | 87.4% | 2.3% | 255 | 86.7% | 2.1% | |
| 7-9 | 175 | 98.9% | 0.8% | 175 | 97.7% | 1.1% | 355 | 89.9% | 1.6% | 236 | 83.9% | 2.4% | |
| 10-16 | 404 | 97.5% | 0.8% | 404 | 96.5% | 0.9% | 440 | 92.7% | 1.2% | 350 | 86.6% | 1.8% | |
| 17+ | 746 | 97.1% | 0.6% | 746 | 94.4% | 0.8% | 671 | 89.9% | 1.2% | 810 | 84.6% | 1.3% | |