| Year | Protected | Not Protected | Protected % |
| 2000 | 0 | 21 | 0.00 |
| 2001 | 0 | 28 | 0.00 |
| 2002 | 33 | 1 | 97.06 |
| 2003 | 38 | 1 | 97.44 |
| 2004 | 32 | 8 | 80.00 |
| 2005 | 34 | 7 | 82.93 |
| 2006 | 36 | 5 | 87.80 |
| 2007 | 20 | 11 | 64.52 |
| 2008 | 15 | 16 | 48.39 |
| 2009 | 9 | 23 | 28.13 |
| 2010 | 18 | 14 | 56.25 |
| 2011 | 5 | 27 | 15.63 |
| 2012 | 3 | 30 | 9.09 |
| 2013 | 3 | 30 | 9.09 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| 2016 | 0 | 35 | 0.00 |
| 2017 | 0 | 36 | 0.00 |
| 2018 | 0 | 37 | 0.00 |
| Totals | 246 | 398 | 38.20 |