| Year | Visitors | Membership |
| 2003 | 231,921 | 8076 |
| 2004 | 151,573 | 10,840 |
| 2005 | 196,923 | 12,845 |
| 2006 | 247,959 | 12,938 |
| 2007 | 248,667 | 9835 |
| 2008 | 317,174 | 11,396 |
| 2009 | 319,500 | 15,438 |
| 2010 | 310,000 | 15,898 |
| 2011 | 227,000 | 17,638 |
| 2012 | 106,800 | 16,322 |