| Year | Protected | Not Protected | Protected % |
| 1998 | 0 | 10 | 0.00 |
| 1999 | 0 | 17 | 0.00 |
| 2000 | 0 | 21 | 0.00 |
| 2001 | 0 | 28 | 0.00 |
| 2002 | 1 | 33 | 2.94 |
| 2003 | 7 | 32 | 17.95 |
| 2004 | 11 | 29 | 27.50 |
| 2005 | 2 | 39 | 4.88 |
| 2006 | 8 | 33 | 19.51 |
| 2007 | 0 | 31 | 0.00 |
| 2008 | 0 | 31 | 0.00 |
| 2009 | 1 | 31 | 3.13 |
| 2010 | 2 | 30 | 6.25 |
| 2011 | 0 | 32 | 0.00 |
| 2012 | 0 | 33 | 0.00 |
| 2013 | 1 | 32 | 3.03 |
| 2014 | 0 | 34 | 0.00 |
| 2015 | 0 | 34 | 0.00 |
| 2016 | 0 | 35 | 0.00 |
| 2017 | 0 | 36 | 0.00 |
| 2018 | 0 | 37 | 0.00 |
| 2019 | 0 | 38 | 0.00 |
| Totals | 33 | 676 | 4.65 |