Year	Percent
1980	0.568
1981	0.603
1982	0.558
1983	0.516
1984	0.516
1985	0.486
1986	0.379
1987	0.384
1988	0.358
1989	0.399
1990	0.474
1991	0.473
1992	0.438
1993	0.429
1994	0.448
1995	0.46
1996	0.467
1997	0.487
1998	0.478
1999	0.48
2000	0.514
2001	0.508
2002	0.506
2003	0.529
2004	0.551
2005	0.551
2006	0.575
2007	0.563
2008	0.565
2009	0.537
2010	0.518
2011	0.533
2012	0.539
2013	0.548
2014	0.553
2015	0.562
2016	0.561
2017	0.545
2018	0.535
2019	0.533
2020	0.532
2021	0.529
2022	0.526
2023	0.522
2024	0.517