| 3 Months | 1 Year | 3 Years | 5 Years | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (Tx 2003 - 2004) | (Tx 2003 - 2004) | (Tx 2001 - 2004) | (Tx 1999 - 2004) | ||||||||||
| N | % | Std. Err. | N | % | Std. Err. | N | % | Std. Err. | N | % | Std. Err. | ||
| Total | All | 242 | 88.8% | 2.0% | 242 | 80.2% | 2.6% | 438 | 62.7% | 2.8% | 563 | 53.0% | 2.9% |
| Yearly Center Volume | 0-1 | 6 | 83.3% | 15.2% | 6 | 66.7% | 19.2% | 22 | 63.6% | 10.3% | 32 | 30.0% | 14.7% |
| 2-7 | 57 | 77.2% | 5.6% | 57 | 70.2% | 6.1% | 66 | 53.6% | 8.0% | 75 | 51.9% | 7.2% | |
| 8+ | 179 | 92.7% | 1.9% | 179 | 83.8% | 2.8% | 350 | 64.7% | 3.0% | 456 | 54.8% | 3.2% | |