Year	Percent
1990	2.07
1991	1.72
1992	2.45
1993	1.9
1994	2.1
1995	1.7
1996	1.5
1997	1.77
1998	1.4
1999	1.14
2000	1.6
2001	0.74
2002	1.24
2003	1.11
2004	0.69
2005	0.62
2006	0.57
2007	0.72
2008	0.91
2009	3.64
2010	3.34
2011	3.57
2012	3.44
2013	3.81
2014	4.07
2015	3.14
2016	1.4
2017	2.58
2018	2.15
2019	2.31