Year	Percent
1990	69
1991	69.8
1992	70.2
1993	71
1994	72.5
1995	73.5
1996	72
1997	74
1998	74.5
1999	75.5
2000	76
2001	77
2002	77.5
2006	79.59
2007	80.45
2009	80.7