Year	Percent
1990	0.6042
1991	0.5852
1992	0.56371
1993	0.54317
1994	0.52873
1995	0.55597
1996	0.54472
1997	0.5201
1998	0.51043
1999	0.51516
2000	0.54131
2001	0.52495
2002	0.51796
2003	0.504
2004	0.48681
2005	0.47305
2006	0.62832
2007	0.62876
2008	0.66102
2009	0.70685
2010	0.69528
2011	0.67619
2012	0.6554
2013	0.63633
2014	0.65057
2015	0.63778
2016	0.62783
2017	0.61949
2018	0.62861
2019	0.57728
2020	0.64185