Year	Percent
1990	2.62115
1991	2.56162
1992	2.48306
1993	2.41056
1994	2.36507
1995	2.77987
1996	2.71141
1997	2.65227
1998	2.59299
1999	2.52347
2000	2.48379
2001	2.49683
2002	2.46857
2003	2.4184
2004	2.40485
2005	2.36376
2006	2.26908
2007	2.22457
2008	2.18317
2009	2.16346
2010	2.14751
2011	2.13113
2012	2.12884
2013	2.09927
2014	2.07812
2015	2.07341
2016	2.08371
2017	2.10314
2018	2.07541
2019	2.05122
2020	2.11629