Year	Percent
1990	0.90172
1991	0.88606
1992	0.89499
1993	0.87398
1994	1.11583
1995	0.83254
1996	0.79505
1997	0.77199
1998	0.66494
1999	0.63769
2000	0.61747
2001	0.55318
2002	0.54073
2003	0.52408
2004	0.49167
2005	0.46487
2006	0.44615
2007	0.42806
2008	0.4246
2009	0.45409
2010	0.46442
2011	0.39891
2012	0.42022
2013	0.41595
2014	0.40292
2015	0.3981
2016	0.39056
2017	0.3823
2018	0.36074
2019	0.36783
2020	0.37003