| Year | Protected | Not Protected | Protected % |
| 2015 | 0 | 34 | 0.00 |
| 2006 | 10 | 26 | 27.78 |
| 2004 | 12 | 32 | 27.27 |
| 2014 | 0 | 34 | 0.00 |
| 2009 | 1 | 33 | 2.94 |
| 2007 | 20 | 13 | 60.61 |
| 2013 | 0 | 34 | 0.00 |
| 2008 | 3 | 31 | 8.82 |
| 1998 | 0 | 15 | 0.00 |
| 2012 | 0 | 34 | 0.00 |
| 2001 | 24 | 9 | 72.73 |
| 2011 | 0 | 34 | 0.00 |
| 2003 | 7 | 35 | 16.67 |
| 2010 | 0 | 33 | 0.00 |
| 2002 | 32 | 6 | 84.21 |
| 2000 | 0 | 28 | 0.00 |
| 2005 | 22 | 23 | 48.89 |
| 1999 | 0 | 22 | 0.00 |
| Totals | 131 | 476 | 21.58 |