| Year | Protected | Not Protected | Protected % |
| 1998 | 10 | 0 | 100.00 |
| 1999 | 17 | 0 | 100.00 |
| 2000 | 21 | 0 | 100.00 |
| 2001 | 28 | 0 | 100.00 |
| 2002 | 34 | 0 | 100.00 |
| 2003 | 39 | 0 | 100.00 |
| 2004 | 40 | 0 | 100.00 |
| 2005 | 37 | 4 | 90.24 |
| 2006 | 34 | 7 | 82.93 |
| 2007 | 30 | 1 | 96.77 |
| 2008 | 29 | 2 | 93.55 |
| 2009 | 32 | 0 | 100.00 |
| 2010 | 12 | 20 | 37.50 |
| 2011 | 0 | 32 | 0.00 |
| 2012 | 1 | 32 | 3.03 |
| 2013 | 0 | 33 | 0.00 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| Totals | 364 | 199 | 64.65 |