| Year | Protected | Not Protected | Protected % |
| 1998 | 0 | 10 | 0.00 |
| 1999 | 1 | 16 | 5.88 |
| 2000 | 0 | 21 | 0.00 |
| 2001 | 0 | 28 | 0.00 |
| 2002 | 34 | 0 | 100.00 |
| 2003 | 23 | 16 | 58.97 |
| 2004 | 34 | 6 | 85.00 |
| 2005 | 41 | 0 | 100.00 |
| 2006 | 36 | 5 | 87.80 |
| 2007 | 32 | -1 | 103.23 |
| 2008 | 31 | 0 | 100.00 |
| 2009 | 32 | 0 | 100.00 |
| 2010 | 32 | 0 | 100.00 |
| 2011 | 29 | 3 | 90.63 |
| 2012 | 29 | 4 | 87.88 |
| 2013 | 32 | 1 | 96.97 |
| 2014 | 19 | 15 | 55.88 |
| 2015 | 2 | 32 | 5.88 |
| 2016 | 0 | 35 | 0.00 |
| 2017 | 0 | 36 | 0.00 |
| 2018 | 0 | 37 | 0.00 |
| Totals | 407 | 264 | 60.66 |