Year	Percent
1991	68.317
1992	69.199
1993	69.577
1994	66.896
1995	68.859
1996	69.901
1997	69.978
1998	70.261
1999	71.024
2000	71.942
2001	72.48
2002	72.982
2003	72.82
2004	72.427
2005	72.787
2006	72.665
2007	73.529
2008	73.294
2009	74.474
2010	73.636
2011	73.952
2012	74.745
2013	74.142
2014	74.788
2015	74.828
2016	75.29
2017	74.118
2018	74.002
2019	74.863
2020	74.848
2021	74.844
2022	74.822