Year	Percent
1990	1.40995
1991	1.14812
1992	1.11599
1993	1.00552
1994	0.91338
1995	0.92431
1996	0.96857
1997	0.87321
1998	0.83756
1999	0.82697
2000	0.55461
2001	0.77044
2002	0.73895
2003	0.70706
2004	0.70929
2005	0.69108
2006	0.59003
2007	0.58288
2008	0.5821
2009	0.59903
2010	0.59945
2011	0.46969
2012	0.44548
2013	0.43008
2014	0.42065
2015	0.41561
2016	0.41109
2017	0.41078
2018	0.41288
2019	0.4141
2020	0.42068