Year	Percent
1990	71.5
1991	76.4
1992	80.8
1993	84.7
1994	77.8
1995	76
1996	72.7
1997	74
1998	74.5
1999	74.5
2000	74.5
2001	76.7
2002	76.7
2003	76.89
2004	86.76
2005	76.82
2006	77.5
2007	78.3
2008	78.51
2009	79.25