Year	Percent
1991	67.444
1992	67.694
1993	72.469
1994	72.025
1995	70.968
1996	69.608
1997	72.341
1998	70.613
1999	66.607
2000	65.081
2001	66.134
2002	66.239
2003	69.58
2004	65.944
2005	64.29
2006	65.321
2007	66.571
2008	67.963
2009	67.417
2010	69.863
2011	73.495
2012	72.591
2013	72.543
2014	71.879
2015	74.759
2016	75.339
2017	75.302
2018	75.306
2019	75.334
2020	75.358
2021	75.357
2022	75.358