Year	Percent
1990	2.79757
1991	2.84202
1992	3.06924
1993	3.12864
1994	3.10137
1995	2.34426
1996	2.38819
1997	2.05546
1998	2.15624
1999	1.95077
2000	1.13987
2001	1.46482
2002	2.3883
2003	1.9764
2004	2.89839
2005	2.76485
2006	1.75096
2007	1.64575
2008	1.70888
2009	2.40647
2010	2.01603
2011	1.48391
2012	1.27258
2013	1.30345
2014	1.39987
2015	1.50096
2016	1.55162
2017	1.59245