| Year | Protected | Not Protected | Protected % |
| 1998 | 0 | 10 | 0.00 |
| 1999 | 5 | 12 | 29.41 |
| 2000 | 21 | 0 | 100.00 |
| 2001 | 28 | 0 | 100.00 |
| 2002 | 34 | 0 | 100.00 |
| 2003 | 39 | 0 | 100.00 |
| 2004 | 40 | 0 | 100.00 |
| 2005 | 41 | 0 | 100.00 |
| 2006 | 36 | 5 | 87.80 |
| 2007 | 31 | 0 | 100.00 |
| 2008 | 28 | 3 | 90.32 |
| 2009 | 27 | 5 | 84.38 |
| 2010 | 24 | 8 | 75.00 |
| 2011 | 12 | 20 | 37.50 |
| 2012 | 0 | 33 | 0.00 |
| 2013 | 0 | 33 | 0.00 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| 2016 | 0 | 35 | 0.00 |
| 2017 | 0 | 36 | 0.00 |
| Totals | 366 | 268 | 57.73 |