| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 31 | 5 | 86.11 |
| 2004 | 40 | 4 | 90.91 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 0 | 34 | 0.00 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 32 | 1 | 96.97 |
| 2013 | 0 | 34 | 0.00 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 10 | 24 | 29.41 |
| 1998 | 14 | 1 | 93.33 |
| 2012 | 0 | 34 | 0.00 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 32 | 1 | 96.97 |
| 2011 | 0 | 34 | 0.00 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 40 | 2 | 95.24 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 38 | 0 | 100.00 |
| 2000 | 28 | 0 | 100.00 |
| 2005 | 39 | 6 | 86.67 |
| 1999 | 22 | 0 | 100.00 |
| Totals | 326 | 451 | 41.96 |