| Year | Protected | Not Protected | Protected % |
| 2015 | 4 | 30 | 11.76 |
| 2006 | 5 | 31 | 13.89 |
| 2004 | 0 | 44 | 0.00 |
| 2014 | 11 | 23 | 32.35 |
| 2009 | 33 | 1 | 97.06 |
| 2007 | 19 | 14 | 57.58 |
| 2013 | 29 | 5 | 85.29 |
| 2008 | 34 | 0 | 100.00 |
| 2012 | 33 | 1 | 97.06 |
| 2018 | 0 | 34 | 0.00 |
| 2011 | 32 | 2 | 94.12 |
| 2016 | 0 | 34 | 0.00 |
| 2010 | 33 | 0 | 100.00 |
| 2017 | 0 | 34 | 0.00 |
| 2005 | 0 | 45 | 0.00 |
| Totals | 233 | 298 | 43.88 |