| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 24 | 12 | 66.67 |
| 2004 | 0 | 44 | 0.00 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 10 | 24 | 29.41 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 21 | 12 | 63.64 |
| 2013 | 0 | 34 | 0.00 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 6 | 28 | 17.65 |
| 2012 | 3 | 31 | 8.82 |
| 2018 | 0 | 34 | 0.00 |
| 2011 | 7 | 27 | 20.59 |
| 2016 | 0 | 34 | 0.00 |
| 2003 | 0 | 42 | 0.00 |
| 2010 | 10 | 23 | 30.30 |
| 2017 | 0 | 34 | 0.00 |
| 2005 | 16 | 29 | 35.56 |
| Totals | 97 | 544 | 15.13 |