| - | Aantal opvragingen 2007=100% | Inkomsten in euro, 2007=100% |
| 2007 | 100 | 100 |
| 2008 | 193 | 198 |
| 2009 | 268 | 298 |
| 2010 | 368 | 432 |
| 2011 | 431 | 538 |
| 2012 | 669 | 827 |
| 2013 | 670 | 799 |
| 2014 | 661 | 719 |
| 2015 | 589 | 634 |
| 2016 | 428,75 | 598,76 |
| 2017 | 348,49 | 497,60 |
| 2018 | 289,02 | 440,55 |
| 2019 | 243,26 | 370,57 |