| Year | Protected | Not Protected | Protected % |
| 1998 | 0 | 10 | 0.00 |
| 1999 | 0 | 17 | 0.00 |
| 2000 | 5 | 16 | 23.81 |
| 2001 | 0 | 28 | 0.00 |
| 2002 | 3 | 31 | 8.82 |
| 2003 | 38 | 1 | 97.44 |
| 2004 | 40 | 0 | 100.00 |
| 2005 | 38 | 3 | 92.68 |
| 2006 | 39 | 2 | 95.12 |
| 2007 | 32 | -1 | 103.23 |
| 2008 | 31 | 0 | 100.00 |
| 2009 | 32 | 0 | 100.00 |
| 2010 | 32 | 0 | 100.00 |
| 2011 | 32 | 0 | 100.00 |
| 2012 | 33 | 0 | 100.00 |
| 2013 | 32 | 1 | 96.97 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| 2016 | 0 | 35 | 0.00 |
| Totals | 387 | 211 | 64.72 |