| Year | Protected | Not Protected | Protected % |
| 1998 | 1 | 9 | 10.00 |
| 1999 | 1 | 16 | 5.88 |
| 2000 | 0 | 21 | 0.00 |
| 2001 | 2 | 26 | 7.14 |
| 2002 | 7 | 27 | 20.59 |
| 2003 | 23 | 16 | 58.97 |
| 2004 | 39 | 1 | 97.50 |
| 2005 | 38 | 3 | 92.68 |
| 2006 | 34 | 7 | 82.93 |
| 2007 | 32 | -1 | 103.23 |
| 2008 | 30 | 1 | 96.77 |
| 2009 | 30 | 2 | 93.75 |
| 2010 | 31 | 1 | 96.88 |
| 2011 | 4 | 28 | 12.50 |
| 2012 | 0 | 33 | 0.00 |
| 2013 | 0 | 33 | 0.00 |
| 2014 | 0 | 34 | 0.00 |
| Totals | 272 | 257 | 51.42 |