Year	Percent
1990	72
1991	74
1992	75
1993	77
1994	79
1995	80.2
1996	81.2
1997	81.7
1998	100
2000	100
2001	100
2002	100
2003	100
2004	100
2005	100
2006	100
2007	100
2008	100
2009	100