| Year | Protected | Not Protected | Protected % |
| 2000 | 0 | 21 | 0.00 |
| 2001 | 21 | 7 | 75.00 |
| 2002 | 27 | 7 | 79.41 |
| 2003 | 28 | 11 | 71.79 |
| 2004 | 40 | 0 | 100.00 |
| 2005 | 38 | 3 | 92.68 |
| 2006 | 30 | 11 | 73.17 |
| 2007 | 30 | 1 | 96.77 |
| 2008 | 14 | 17 | 45.16 |
| 2009 | 29 | 3 | 90.63 |
| 2010 | 11 | 21 | 34.38 |
| 2011 | 15 | 17 | 46.88 |
| 2012 | 2 | 31 | 6.06 |
| 2013 | 0 | 33 | 0.00 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| 2016 | 0 | 35 | 0.00 |
| 2017 | 0 | 36 | 0.00 |
| Totals | 285 | 322 | 46.95 |