| Year | Protected | Not Protected | Protected % |
| 1998 | 10 | 0 | 100.00 |
| 1999 | 17 | 0 | 100.00 |
| 2000 | 12 | 9 | 57.14 |
| 2001 | 25 | 3 | 89.29 |
| 2002 | 32 | 2 | 94.12 |
| 2003 | 30 | 9 | 76.92 |
| 2004 | 34 | 6 | 85.00 |
| 2005 | 11 | 30 | 26.83 |
| 2006 | 34 | 7 | 82.93 |
| 2007 | 19 | 12 | 61.29 |
| 2008 | 3 | 28 | 9.68 |
| 2009 | 1 | 31 | 3.13 |
| 2010 | 1 | 31 | 3.13 |
| 2011 | 0 | 32 | 0.00 |
| 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 |
| Totals | 229 | 369 | 38.29 |