| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 0 | 36 | 0.00 |
| 2004 | 5 | 39 | 11.36 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 1 | 33 | 2.94 |
| 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 | 5 | 10 | 33.33 |
| 2012 | 0 | 34 | 0.00 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 17 | 16 | 51.52 |
| 2011 | 0 | 34 | 0.00 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 7 | 35 | 16.67 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 7 | 31 | 18.42 |
| 2000 | 5 | 23 | 17.86 |
| 2005 | 5 | 40 | 11.11 |
| 1999 | 11 | 11 | 50.00 |
| Totals | 64 | 713 | 8.24 |