Year	Percent
1980	0.683
1981	0.695
1982	0.718
1983	0.713
1984	0.633
1985	0.566
1986	0.566
1987	0.568
1988	0.581
1989	0.595
1990	0.589
1991	0.572
1992	0.515
1993	0.516
1994	0.523
1995	0.528
1996	0.539
1997	0.544
1998	0.527
1999	0.525
2000	0.523
2001	0.526
2002	0.529
2003	0.534
2004	0.541
2005	0.541
2006	0.541
2007	0.547
2008	0.553
2009	0.562
2010	0.575
2011	0.572
2012	0.592
2013	0.613
2014	0.629
2015	0.645
2016	0.668
2017	0.687
2018	0.705
2019	0.727
2020	0.748
2021	0.771
2022	0.795
2023	0.819
2024	0.844