| Previous PA/KP Tx | Year | |||||||||
| 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | |
| Total | 74 | 89 | 136 | 155 | 153 | 181 | 278 | 453 | 671 | 781 |
| No | 43 | 54 | 82 | 93 | 94 | 101 | 177 | 316 | 498 | 597 |
| Yes | 31 | 35 | 54 | 62 | 59 | 80 | 101 | 137 | 173 | 184 |
| Total (%) | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% |
| No | 58.1% | 60.7% | 60.3% | 60.0% | 61.4% | 55.8% | 63.7% | 69.8% | 74.2% | 76.4% |
| Yes | 41.9% | 39.3% | 39.7% | 40.0% | 38.6% | 44.2% | 36.3% | 30.2% | 25.8% | 23.6% |