| Year | Protected | Not Protected | Protected % |
| 2015 | 3 | 31 | 8.82 |
| 2006 | 0 | 36 | 0.00 |
| 2004 | 0 | 44 | 0.00 |
| 2014 | 1 | 33 | 2.94 |
| 2009 | 0 | 34 | 0.00 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 0 | 33 | 0.00 |
| 2013 | 3 | 31 | 8.82 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 0 | 34 | 0.00 |
| 1998 | 0 | 15 | 0.00 |
| 2012 | 0 | 34 | 0.00 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 0 | 33 | 0.00 |
| 2011 | 0 | 34 | 0.00 |
| 2016 | 4 | 30 | 11.76 |
| 2003 | 0 | 42 | 0.00 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 4 | 30 | 11.76 |
| 2002 | 0 | 38 | 0.00 |
| 2000 | 0 | 28 | 0.00 |
| 2005 | 0 | 45 | 0.00 |
| 1999 | 0 | 22 | 0.00 |
| Totals | 15 | 762 | 1.93 |