Year	Percent
1990	0.63886
1991	0.61897
1992	0.59933
1993	0.58003
1994	0.56109
1995	0.86767
1996	0.83795
1997	0.81868
1998	0.77936
1999	0.74961
2000	0.71696
2001	0.6819
2002	0.93007
2003	0.49784
2004	0.36228
2005	0.34271
2007	0.30825
2008	0.29299
2009	0.3682
2010	0.35121
2011	0.33574
2012	0.32182
2013	0.30895
2014	0.29706
2015	0.28618
2016	0.30327
2017	0.20221
2018	0.28369
2019	0.18929
2020	0.18946