| Year | Percentage |
|---|---|
| 1986 | 71.18 |
| 1987 | 69.03 |
| 1988 | 59.39 |
| 1989 | 65.21 |
| 1990 | 80.50 |
| 1991 | 80.40 |
| 1992 | 78.41 |
| 1993 | 88.02 |
| 1994 | 89.17 |
| 1995 | 92.66 |
| 1996 | 84.45 |
| 1997 | 83.33 |
| 1998 | 78.28 |
| 1999 | 92.85 |
| 2000 | 86.70 |
| 2001 | 92.52 |
| 2002 | 98.40 |
| 2003 | 99.44 |
| Year | Percentage |
|---|---|
| 2004 | 94.25 |
| 2005 | 93.82 |
| 2006 | 98.50 |
| 2007 | 99.00 |
| 2008 | 98.48 |
| 2009 | 96.20 |
| 2010 | 100 |
| 2011 | 99.51 |
| 2012 | 99.51 |
| 2013 | 100 |
| 2014 | 100 |
| 2015 | 100 |
| 2016 | 97.20 |
| 2017 | 100 |
| 2018 | 100 |
| 2019 | 97.80 |
| 2020 | 95.80 |
| 2021 | 100 |
