| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 25 | 11 | 69.44 |
| 2004 | 23 | 21 | 52.27 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 4 | 30 | 11.76 |
| 2007 | 8 | 25 | 24.24 |
| 2013 | 0 | 34 | 0.00 |
| 2008 | 2 | 32 | 5.88 |
| 2012 | 0 | 34 | 0.00 |
| 2001 | 1 | 32 | 3.03 |
| 2011 | 5 | 29 | 14.71 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 24 | 18 | 57.14 |
| 2010 | 0 | 33 | 0.00 |
| 2002 | 38 | 0 | 100.00 |
| 2000 | 0 | 28 | 0.00 |
| 2005 | 23 | 22 | 51.11 |
| Totals | 153 | 451 | 25.33 |