| Year | Protected | Not Protected | Protected % |
| 1999 | 0 | 17 | 0.00 |
| 2000 | 15 | 6 | 71.43 |
| 2001 | 28 | 0 | 100.00 |
| 2002 | 34 | 0 | 100.00 |
| 2003 | 39 | 0 | 100.00 |
| 2004 | 40 | 0 | 100.00 |
| 2005 | 41 | 0 | 100.00 |
| 2006 | 34 | 7 | 82.93 |
| 2007 | 11 | 20 | 35.48 |
| 2008 | 24 | 7 | 77.42 |
| 2009 | 4 | 28 | 12.50 |
| 2010 | 8 | 24 | 25.00 |
| 2011 | 25 | 7 | 78.13 |
| 2012 | 3 | 30 | 9.09 |
| 2013 | 8 | 25 | 24.24 |
| 2014 | 2 | 32 | 5.88 |
| 2015 | 0 | 34 | 0.00 |
| 2016 | 0 | 35 | 0.00 |
| 2017 | 0 | 36 | 0.00 |
| 2018 | 0 | 37 | 0.00 |
| Totals | 316 | 345 | 47.81 |