| Previous PA/KP Tx | Year | |||||||||
| 1994 | 1995 | 1996 | 1997 | 1998 | 1999 | 2000 | 2001 | 2002 | 2003 | |
| Total | 164 | 181 | 201 | 221 | 272 | 246 | 312 | 383 | 403 | 452 |
| No | 151 | 169 | 192 | 210 | 257 | 235 | 291 | 353 | 381 | 413 |
| Yes | 13 | 12 | 9 | 11 | 15 | 11 | 21 | 30 | 22 | 39 |
| Total (%) | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% | 100.0% |
| No | 92.1% | 93.4% | 95.5% | 95.0% | 94.5% | 95.5% | 93.3% | 92.2% | 94.5% | 91.4% |
| Yes | 7.9% | 6.6% | 4.5% | 5.0% | 5.5% | 4.5% | 6.7% | 7.8% | 5.5% | 8.6% |