| Year | Protected | Not Protected | Protected % |
| 1998 | 0 | 10 | 0.00 |
| 1999 | 0 | 17 | 0.00 |
| 2000 | 0 | 21 | 0.00 |
| 2001 | 4 | 24 | 14.29 |
| 2002 | 0 | 34 | 0.00 |
| 2003 | 1 | 38 | 2.56 |
| 2004 | 1 | 39 | 2.50 |
| 2005 | 0 | 41 | 0.00 |
| 2006 | 0 | 41 | 0.00 |
| 2007 | 0 | 31 | 0.00 |
| 2008 | 0 | 31 | 0.00 |
| 2009 | 0 | 32 | 0.00 |
| 2010 | 0 | 32 | 0.00 |
| 2011 | 0 | 32 | 0.00 |
| 2012 | 0 | 33 | 0.00 |
| 2013 | 0 | 33 | 0.00 |
| Totals | 6 | 489 | 1.21 |