Year	Percent
1990	0.57838
1991	0.57104
1992	0.7988
1993	0.89639
1994	1.00489
1995	0.80771
1996	0.69308
1997	0.66707
1998	0.66003
1999	0.69281
2000	0.6927
2001	0.65977
2002	0.67253
2003	0.66238
2004	0.09624
2005	2.60995
2006	0.54256
2007	0.53398
2008	0.5215
2009	0.57217
2010	0.56863
2011	0.50969
2012	0.49347
2013	0.45721
2014	0.43952
2015	0.43604
2016	0.42875
2017	0.42679
2018	0.43278
2019	0.40233
2020	0.40162