| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 28 | 8 | 77.78 |
| 2004 | 41 | 3 | 93.18 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 34 | 0 | 100.00 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 33 | 0 | 100.00 |
| 2013 | 0 | 34 | 0.00 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 32 | 2 | 94.12 |
| 2012 | 0 | 34 | 0.00 |
| 2018 | 0 | 34 | 0.00 |
| 2001 | 28 | 5 | 84.85 |
| 2011 | 8 | 26 | 23.53 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 12 | 30 | 28.57 |
| 2010 | 32 | 1 | 96.97 |
| 2017 | 0 | 34 | 0.00 |
| 2002 | 36 | 2 | 94.74 |
| 2000 | 0 | 28 | 0.00 |
| 2005 | 28 | 17 | 62.22 |
| Totals | 312 | 428 | 42.16 |