| Previous PA/KP Tx | Year | |||||||||
| 1993 | 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | |
| Total | 132 | 164 | 182 | 201 | 221 | 272 | 248 | 315 | 387 | 408 |
| No | 121 | 151 | 170 | 192 | 210 | 257 | 237 | 294 | 357 | 386 |
| Yes | 11 | 13 | 12 | 9 | 11 | 15 | 11 | 21 | 30 | 22 |
| Total (%) | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% |
| No | 91.7% | 92.1% | 93.4% | 95.5% | 95.0% | 94.5% | 95.6% | 93.3% | 92.2% | 94.6% |
| Yes | 8.3% | 7.9% | 6.6% | 4.5% | 5.0% | 5.5% | 4.4% | 6.7% | 7.8% | 5.4% |