Year	Percent
1990	0.31434
1991	0.31058
1992	0.50607
1993	0.31705
1994	0.31608
1995	0.44227
1996	0.94365
1997	0.9825
1998	0.35771
1999	0.23359
2000	0.22837
2001	0.34054
2002	0.69767
2003	0.67047
2004	0.63362
2005	0.62455
2006	0.52341
2007	0.51834
2008	0.51161
2009	0.48091
2010	0.4733
2011	0.46619
2012	0.45942
2013	0.45289
2014	0.36152
2015	0.3554
2016	0.34924
2017	0.36337
2018	0.3375
2019	0.34741
2020	0.34058