Year	Percent
1990	73.687
1991	73.696
1992	73.148
1993	73.008
1994	72.657
1995	72.135
1996	70.163
1997	67.068
1998	66.011
1999	65.203
2000	64.831
2001	62.998
2002	62.35
2003	62.145
2004	61.488
2005	61.527
2006	61.055
2007	60.497
2008	60.123
2009	60.547
2010	61.473
2011	61.057
2012	60.643
2013	60.938
2014	61.308
2015	62.093
2016	62.203
2017	61.8
2018	61.689
2019	61.833
2020	62.122
2021	61.637
2022	61.193
2023	60.88
2024	60.74
2025	60.757
2026	60.553
2027	60.389
2028	60.306
2029	60.304
2030	60.357