| Year | Protected | Not Protected | Protected % |
| 2004 | 10 | 30 | 25.00 |
| 2005 | 39 | 2 | 95.12 |
| 2006 | 35 | 6 | 85.37 |
| 2007 | 32 | -1 | 103.23 |
| 2008 | 28 | 3 | 90.32 |
| 2009 | 31 | 1 | 96.88 |
| 2010 | 32 | 0 | 100.00 |
| 2011 | 32 | 0 | 100.00 |
| 2012 | 33 | 0 | 100.00 |
| 2013 | 33 | 0 | 100.00 |
| 2014 | 34 | 0 | 100.00 |
| 2015 | 5 | 29 | 14.71 |
| 2016 | 0 | 35 | 0.00 |
| 2017 | 0 | 36 | 0.00 |
| 2018 | 0 | 37 | 0.00 |
| 2019 | 0 | 38 | 0.00 |
| 2020 | 0 | 39 | 0.00 |
| 2021 | 0 | 30 | 0.00 |
| Totals | 344 | 285 | 54.69 |