Year	Percent
1990	0.18138
1991	0.38289
1992	0.93095
1993	2.0684
1994	2.53286
1995	3.11264
1996	3.56024
1997	2.94363
1998	2.79303
1999	3.28679
2000	3.84155
2001	4.52605
2002	3.52177
2003	3.12524
2004	3.4187
2005	2.56968
2006	1.8738
2007	1.38134
2008	1.33466
2009	3.36905
2010	5.72482
2011	4.45042
2012	3.49875
2013	2.61189
2014	2.2702
2015	1.71295
2016	1.62805
2017	1.46177