| Year | Protected | Not Protected | Protected % |
| 2015 | 9 | 25 | 26.47 |
| 2006 | 32 | 4 | 88.89 |
| 2004 | 43 | 1 | 97.73 |
| 2014 | 3 | 31 | 8.82 |
| 2009 | 34 | 0 | 100.00 |
| 2007 | 33 | 0 | 100.00 |
| 2013 | 31 | 3 | 91.18 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 34 | 0 | 100.00 |
| 2012 | 34 | 0 | 100.00 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 0 | 33 | 0.00 |
| 2011 | 7 | 27 | 20.59 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 1 | 41 | 2.38 |
| 2010 | 33 | 0 | 100.00 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 0 | 38 | 0.00 |
| 2005 | 41 | 4 | 91.11 |
| Totals | 335 | 343 | 49.41 |