| Year | Protected | Not Protected | Protected % |
| 2001 | 0 | 28 | 0.00 |
| 2002 | 32 | 2 | 94.12 |
| 2003 | 34 | 5 | 87.18 |
| 2004 | 29 | 11 | 72.50 |
| 2005 | 34 | 7 | 82.93 |
| 2006 | 33 | 8 | 80.49 |
| 2007 | 23 | 8 | 74.19 |
| 2008 | 23 | 8 | 74.19 |
| 2009 | 12 | 20 | 37.50 |
| 2010 | 10 | 22 | 31.25 |
| 2011 | 6 | 26 | 18.75 |
| 2012 | 0 | 33 | 0.00 |
| 2013 | 1 | 32 | 3.03 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| 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 |
| 2022 | 0 | 41 | 0.00 |
| Totals | 237 | 534 | 30.74 |