| 2000 | 2005 | 2010 | 2011 | 2012 | |
|---|---|---|---|---|---|
| Groningen | 2.1 | 2.1 | 1.9 | 1.9 | 1.7 |
| Utrecht | 1.7 | 1.6 | 1.3 | 1.3 | 1.1 |
| Zuid-Holland | 0.9 | 1.2 | 1.1 | 1.1 | 0.9 |
| Noord-Holland | 1.1 | 0.8 | 1.1 | 1.1 | 0.9 |
| Gelderland | 0.7 | 0.8 | 0.9 | 0.9 | 0.8 |
| Overijssel | 1.1 | 1.1 | 0.9 | 0.9 | 0.8 |
| Noord-Brabant | 0.9 | 0.9 | 0.9 | 0.9 | 0.8 |
| Friesland | 0.8 | 0.8 | 0.8 | 0.8 | 0.7 |
| Limburg | 0.7 | 0.7 | 0.9 | 0.9 | 0.7 |
| Flevoland | 0.1 | 0.2 | 0.8 | 0.7 | 0.6 |
| Drenthe | 0.1 | 0.1 | 0.5 | 0.5 | 0.5 |
| Zeeland | 0.3 | 0.3 | 0.5 | 0.5 | 0.4 |