Year	Percent
1990	76.27
1991	66.625
1992	70.847
1993	73.719
1994	75.075
1995	75.899
1996	75.504
1997	75.891
1998	76.223
1999	76.079
2000	76.263
2001	75.752
2002	75.338
2003	75.646
2004	75.936
2005	76.181
2006	75.926
2007	76.701
2008	75.843
2009	75.732
2010	75.37
2011	74.942
2012	74.47
2013	73.934
2014	74.087
2015	74.252
2016	74.093
2017	73.665
2018	73.188
2019	72.672
2020	72.128
2021	71.581
2022	71.03
2023	70.488
2024	69.978
2025	69.517
2026	69.078
2027	68.702
2028	68.38
2029	68.106
2030	67.872