| Year | Protected | Not Protected | Protected % |
| 2001 | 0 | 28 | 0.00 |
| 2002 | 0 | 34 | 0.00 |
| 2003 | 1 | 38 | 2.56 |
| 2004 | 0 | 40 | 0.00 |
| 2005 | 0 | 41 | 0.00 |
| 2006 | 0 | 41 | 0.00 |
| 2007 | 14 | 17 | 45.16 |
| 2008 | 6 | 25 | 19.35 |
| 2009 | 0 | 32 | 0.00 |
| 2010 | 9 | 23 | 28.13 |
| 2011 | 2 | 30 | 6.25 |
| 2012 | 19 | 14 | 57.58 |
| 2013 | 1 | 32 | 3.03 |
| 2014 | 20 | 14 | 58.82 |
| 2015 | 6 | 28 | 17.65 |
| 2016 | 0 | 35 | 0.00 |
| 2017 | 0 | 36 | 0.00 |
| 2018 | 0 | 37 | 0.00 |
| Totals | 78 | 545 | 12.52 |