| Year | Protected | Not Protected | Protected % |
| 1999 | 0 | 17 | 0.00 |
| 2000 | 0 | 21 | 0.00 |
| 2001 | 0 | 28 | 0.00 |
| 2002 | 0 | 34 | 0.00 |
| 2003 | 0 | 39 | 0.00 |
| 2004 | 0 | 40 | 0.00 |
| 2005 | 1 | 40 | 2.44 |
| 2006 | 0 | 41 | 0.00 |
| 2007 | 1 | 30 | 3.23 |
| 2008 | 5 | 26 | 16.13 |
| 2009 | 0 | 32 | 0.00 |
| 2010 | 1 | 31 | 3.13 |
| 2011 | 5 | 27 | 15.63 |
| 2012 | 0 | 33 | 0.00 |
| 2013 | 0 | 33 | 0.00 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| 2016 | 0 | 35 | 0.00 |
| Totals | 13 | 575 | 2.21 |