| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 32 | 4 | 88.89 |
| 2004 | 41 | 3 | 93.18 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 1 | 33 | 2.94 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 32 | 1 | 96.97 |
| 2013 | 0 | 34 | 0.00 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 20 | 14 | 58.82 |
| 1998 | 4 | 11 | 26.67 |
| 2012 | 0 | 34 | 0.00 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 30 | 3 | 90.91 |
| 2011 | 0 | 34 | 0.00 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 39 | 3 | 92.86 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 36 | 2 | 94.74 |
| 2000 | 1 | 27 | 3.57 |
| 2005 | 35 | 10 | 77.78 |
| 1999 | 7 | 15 | 31.82 |
| Totals | 278 | 499 | 35.78 |