| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 12 | 24 | 33.33 |
| 2004 | 3 | 41 | 6.82 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 0 | 34 | 0.00 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 1 | 32 | 3.03 |
| 2013 | 0 | 34 | 0.00 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 0 | 34 | 0.00 |
| 1998 | 7 | 8 | 46.67 |
| 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 | 1 | 41 | 2.38 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 0 | 38 | 0.00 |
| 2000 | 0 | 28 | 0.00 |
| 2005 | 18 | 27 | 40.00 |
| 1999 | 4 | 18 | 18.18 |
| Totals | 46 | 731 | 5.92 |