Year	Percent
1991	75.224
1992	75.46
1993	75.806
1994	76.27
1995	76.585
1996	76.404
1997	76.863
1998	77.379
1999	78.473
2000	77.992
2001	77.478
2002	76.913
2003	76.387
2004	75.823
2005	75.23
2006	74.645
2007	74.05
2008	73.403
2009	73.106
2010	72.867
2011	73.215
2012	73.616
2013	73.873
2014	74.514
2015	74.546
2016	74.922
2017	75.141
2018	74.944
2019	74.74
2020	74.528
2021	74.32
2022	74.106