| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 32 | 4 | 88.89 |
| 2004 | 44 | 0 | 100.00 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 27 | 7 | 79.41 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 32 | 1 | 96.97 |
| 2013 | 0 | 34 | 0.00 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 26 | 8 | 76.47 |
| 1998 | 0 | 15 | 0.00 |
| 2012 | 0 | 34 | 0.00 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 1 | 32 | 3.03 |
| 2011 | 1 | 33 | 2.94 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 40 | 2 | 95.24 |
| 2010 | 32 | 1 | 96.97 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 18 | 20 | 47.37 |
| 2000 | 0 | 28 | 0.00 |
| 2005 | 40 | 5 | 88.89 |
| 1999 | 0 | 22 | 0.00 |
| Totals | 293 | 484 | 37.71 |