| Year | Protected | Not Protected | Protected % |
| 1998 | 10 | 0 | 100.00 |
| 1999 | 17 | 0 | 100.00 |
| 2000 | 21 | 0 | 100.00 |
| 2001 | 28 | 0 | 100.00 |
| 2002 | 34 | 0 | 100.00 |
| 2003 | 38 | 1 | 97.44 |
| 2004 | 33 | 7 | 82.50 |
| 2005 | 30 | 11 | 73.17 |
| 2006 | 32 | 9 | 78.05 |
| 2007 | 11 | 20 | 35.48 |
| 2008 | 15 | 16 | 48.39 |
| 2009 | 3 | 29 | 9.38 |
| 2010 | 1 | 31 | 3.13 |
| 2011 | 0 | 32 | 0.00 |
| 2012 | 0 | 33 | 0.00 |
| 2013 | 0 | 33 | 0.00 |
| Totals | 273 | 222 | 55.15 |