| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 13 | 23 | 36.11 |
| 2004 | 1 | 43 | 2.27 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 9 | 25 | 26.47 |
| 2007 | 14 | 19 | 42.42 |
| 2013 | 12 | 22 | 35.29 |
| 2008 | 2 | 32 | 5.88 |
| 2012 | 6 | 28 | 17.65 |
| 2018 | 0 | 34 | 0.00 |
| 2011 | 3 | 31 | 8.82 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 0 | 42 | 0.00 |
| 2010 | 3 | 30 | 9.09 |
| 2017 | 0 | 34 | 0.00 |
| 2005 | 0 | 45 | 0.00 |
| Totals | 63 | 510 | 10.99 |