| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 0 | 36 | 0.00 |
| 2004 | 0 | 44 | 0.00 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 0 | 34 | 0.00 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 0 | 33 | 0.00 |
| 2013 | 0 | 34 | 0.00 |
| 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 | 12 | 21 | 36.36 |
| 2011 | 0 | 34 | 0.00 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 3 | 39 | 7.14 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 3 | 35 | 7.89 |
| 2000 | 5 | 23 | 17.86 |
| 2005 | 0 | 45 | 0.00 |
| 1999 | 1 | 21 | 4.55 |
| Totals | 24 | 753 | 3.09 |