| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 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 | 18 | 15 | 54.55 |
| 2013 | 2 | 32 | 5.88 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 0 | 34 | 0.00 |
| 1998 | 0 | 15 | 0.00 |
| 2012 | 3 | 31 | 8.82 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 4 | 29 | 12.12 |
| 2011 | 8 | 26 | 23.53 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 0 | 42 | 0.00 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 1 | 37 | 2.63 |
| 2000 | 6 | 22 | 21.43 |
| 2005 | 0 | 45 | 0.00 |
| 1999 | 5 | 17 | 22.73 |
| Totals | 48 | 729 | 6.18 |