| Year | Protected | Not Protected | Protected % |
| 2015 | 18 | 16 | 52.94 |
| 2006 | 0 | 36 | 0.00 |
| 2004 | 27 | 17 | 61.36 |
| 2014 | 21 | 13 | 61.76 |
| 2009 | 0 | 34 | 0.00 |
| 2020 | 2 | 32 | 5.88 |
| 2007 | 1 | 32 | 3.03 |
| 2013 | 4 | 30 | 11.76 |
| 2019 | 3 | 31 | 8.82 |
| 2008 | 2 | 32 | 5.88 |
| 2012 | 0 | 34 | 0.00 |
| 2018 | 5 | 29 | 14.71 |
| 2001 | 0 | 33 | 0.00 |
| 2011 | 0 | 34 | 0.00 |
| 2016 | 22 | 12 | 64.71 |
| 2003 | 0 | 42 | 0.00 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 3 | 31 | 8.82 |
| 2002 | 0 | 38 | 0.00 |
| 2005 | 3 | 42 | 6.67 |
| Totals | 111 | 601 | 15.59 |