Year	Percent
1990	2.24923
1991	2.16492
1992	1.57077
1993	1.22642
1994	1.62885
1995	1.36042
1996	1.30768
1997	1.28161
1998	1.25342
1999	1.22164
2000	1.18387
2001	1.16824
2002	1.13922
2003	1.0959
2004	1.02468
2005	1.01823
2007	0.96666
2008	0.94081
2009	0.91581
2010	0.88864
2011	0.86471
2012	0.84096
2013	0.81686
2014	0.90697
2015	0.88642
2016	0.86617
2017	0.74065
2018	0.6761
2019	0.89507
2020	0.87346