| Year | Protected | Not Protected | Protected % |
| 2001 | 0 | 28 | 0.00 |
| 2002 | 25 | 9 | 73.53 |
| 2003 | 35 | 4 | 89.74 |
| 2004 | 39 | 1 | 97.50 |
| 2005 | 37 | 4 | 90.24 |
| 2006 | 32 | 9 | 78.05 |
| 2007 | 18 | 13 | 58.06 |
| 2008 | 31 | 0 | 100.00 |
| 2009 | 28 | 4 | 87.50 |
| 2010 | 31 | 1 | 96.88 |
| 2011 | 17 | 15 | 53.13 |
| 2012 | 29 | 4 | 87.88 |
| 2013 | 1 | 32 | 3.03 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| 2016 | 0 | 35 | 0.00 |
| 2017 | 0 | 36 | 0.00 |
| Totals | 323 | 263 | 55.12 |