| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 3 | 33 | 8.33 |
| 2004 | 36 | 8 | 81.82 |
| 2014 | 1 | 33 | 2.94 |
| 2009 | 0 | 34 | 0.00 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 0 | 33 | 0.00 |
| 2013 | 2 | 32 | 5.88 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 0 | 34 | 0.00 |
| 1998 | 1 | 14 | 6.67 |
| 2012 | 3 | 31 | 8.82 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 33 | 0 | 100.00 |
| 2011 | 8 | 26 | 23.53 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 36 | 6 | 85.71 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 37 | 1 | 97.37 |
| 2000 | 28 | 0 | 100.00 |
| 2005 | 37 | 8 | 82.22 |
| 1999 | 22 | 0 | 100.00 |
| Totals | 247 | 530 | 31.79 |