Year	Percent
1980	0.804
1981	0.791
1982	0.82
1983	0.847
1984	0.86
1985	0.83
1986	0.821
1987	0.797
1988	0.758
1989	0.689
1990	0.625
1991	0.531
1992	0.435
1993	0.434
1994	0.438
1995	0.452
1996	0.453
1997	0.409
1998	0.379
1999	0.362
2000	0.356
2001	0.367
2002	0.375
2003	0.38
2004	0.391
2005	0.389
2006	0.399
2007	0.404
2008	0.429
2009	0.407
2010	0.372
2011	0.364
2012	0.361
2013	0.361
2014	0.361
2015	0.363
2016	0.368
2017	0.38
2018	0.382
2019	0.381
2020	0.379
2021	0.377
2022	0.375
2023	0.373
2024	0.371