Year	Percent
1991	80.048
1992	79.834
1993	79.785
1994	79.37
1995	79.798
1996	79.85
1997	80.148
1998	79.808
1999	79.596
2000	79.224
2001	78.713
2002	80.406
2003	79.344
2004	81.762
2005	82.484
2006	80.648
2007	77.711
2008	75.587
2009	74.79
2010	72.114
2011	69.292
2012	66.02
2013	68.881
2014	70.884
2015	72.172
2016	71.958
2017	71.984
2018	71.759
2019	71.461
2020	71.146
2021	70.841
2022	70.531