| 1990 | 2000 | 2005 | 2010 | 2011 | 2012 | |
|---|---|---|---|---|---|---|
| Noord-Brabant | 607 | 1.838 | 1.721 | 1.302 | 1.631 | 1.222 |
| Zuid-Holland | 246 | 433 | 492 | 488 | 493 | 433 |
| Noord-Holland | 186 | 301 | 272 | 289 | 324 | 220 |
| Limburg | 76 | 191 | 226 | 175 | 277 | 200 |
| Gelderland | 120 | 243 | 297 | 273 | 262 | 194 |
| Utrecht | 82 | 173 | 206 | 189 | 125 | 130 |
| Overijssel | 102 | 109 | 134 | 155 | 147 | 116 |
| Flevoland | 8 | 29 | 21 | 19 | 17 | 26 |
| Friesland | 28 | 31 | 37 | 44 | 39 | 24 |
| Groningen | 16 | 46 | 38 | 40 | 47 | 22 |
| Drenthe | 28 | 40 | 29 | 29 | 21 | 22 |
| Zeeland | 12 | 25 | 19 | 23 | 28 | 21 |