| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 18 | 18 | 50.00 |
| 2004 | 31 | 13 | 70.45 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 0 | 34 | 0.00 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 6 | 27 | 18.18 |
| 2013 | 0 | 34 | 0.00 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 1 | 33 | 2.94 |
| 1998 | 4 | 11 | 26.67 |
| 2012 | 0 | 34 | 0.00 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 0 | 33 | 0.00 |
| 2011 | 0 | 34 | 0.00 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 41 | 1 | 97.62 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 1 | 37 | 2.63 |
| 2000 | 3 | 25 | 10.71 |
| 2005 | 15 | 30 | 33.33 |
| 1999 | 1 | 21 | 4.55 |
| Totals | 121 | 656 | 15.57 |