Year	Percent
1990	90.24
1991	90.09
1992	90.83
1993	90.94
1994	91.24
1995	91.54
1996	91.32
1997	90.18
1998	89.89
1999	91.98
2000	92.99
2001	91.79
2002	92.49
2003	91.55
2004	90.44
2005	89.1
2006	89.8
2007	89.48
2008	88.92
2009	88.38
2010	88.5
2011	88.34
2012	88.37
2013	88.84
2014	90.25
2015	91.17
2016	92.1
2017	91.48
2018	90.9
2019	90.92