| Year | Protected | Not Protected | Protected % |
| 2015 | 11 | 23 | 32.35 |
| 2006 | 0 | 36 | 0.00 |
| 2004 | 2 | 42 | 4.55 |
| 2014 | 15 | 19 | 44.12 |
| 2009 | 0 | 34 | 0.00 |
| 2020 | 0 | 34 | 0.00 |
| 2007 | 0 | 33 | 0.00 |
| 2013 | 11 | 23 | 32.35 |
| 2019 | 0 | 34 | 0.00 |
| 2008 | 0 | 34 | 0.00 |
| 1998 | 0 | 15 | 0.00 |
| 2012 | 10 | 24 | 29.41 |
| 2018 | 3 | 31 | 8.82 |
| 2001 | 32 | 1 | 96.97 |
| 2011 | 5 | 29 | 14.71 |
| 2016 | 6 | 28 | 17.65 |
| 2003 | 0 | 42 | 0.00 |
| 2010 | 0 | 33 | 0.00 |
| 2017 | 13 | 21 | 38.24 |
| 2002 | 28 | 10 | 73.68 |
| 2000 | 28 | 0 | 100.00 |
| 2005 | 14 | 31 | 31.11 |
| 1999 | 0 | 22 | 0.00 |
| Totals | 178 | 599 | 22.91 |