Year	Percent
1990	0.43043
1991	0.42369
1992	0.41377
1993	0.40403
1994	0.39438
1995	0.64528
1996	0.64518
1997	0.62663
1998	0.6147
1999	0.59409
2000	0.60254
2001	0.58882
2002	0.58899
2003	0.58742
2004	0.62814
2005	0.72211
2006	0.60035
2007	0.5847
2008	0.57396
2009	0.57181
2010	0.56025
2011	0.56034
2012	0.57323
2013	0.57697
2014	0.57672
2015	0.58714
2016	0.62569
2017	0.63691
2018	0.63752
2019	0.60773
2020	0.6174