| 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 | 33 | 1 | 97.06 |
| 2003 | 39 | 0 | 100.00 |
| 2004 | 39 | 1 | 97.50 |
| 2005 | 39 | 2 | 95.12 |
| 2006 | 36 | 5 | 87.80 |
| 2007 | 30 | 1 | 96.77 |
| 2008 | 29 | 2 | 93.55 |
| 2009 | 0 | 32 | 0.00 |
| 2010 | 0 | 32 | 0.00 |
| 2011 | 0 | 32 | 0.00 |
| 2012 | 0 | 33 | 0.00 |
| 2013 | 0 | 33 | 0.00 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| Totals | 321 | 242 | 57.02 |