| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 0 | 36 | 0.00 |
| 2004 | 2 | 42 | 4.55 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 0 | 34 | 0.00 |
| 2007 | 0 | 33 | 0.00 |
| 2013 | 0 | 34 | 0.00 |
| 2008 | 0 | 34 | 0.00 |
| 1998 | 4 | 11 | 26.67 |
| 2012 | 0 | 34 | 0.00 |
| 2001 | 2 | 31 | 6.06 |
| 2011 | 0 | 34 | 0.00 |
| 2003 | 2 | 40 | 4.76 |
| 2010 | 0 | 33 | 0.00 |
| 2002 | 2 | 36 | 5.26 |
| 2000 | 5 | 23 | 17.86 |
| 2005 | 0 | 45 | 0.00 |
| 1999 | 7 | 15 | 31.82 |
| Totals | 24 | 583 | 3.95 |