Year	Percent
1990	0.52
1991	1.28
1992	3.29
1993	6.29
1994	7.32
1995	9.41
1996	9.51
1997	10.1
1998	9.6
1999	11.17
2000	13.28
2001	12.35
2002	8.94
2003	9.94
2004	9.18
2005	7.74
2006	5.57
2007	4.17
2008	4.86
2009	12.82
2010	15.13
2011	11.47
2012	9.51
2013	8.27
2014	7.16
2015	5.55
2016	5.93
2017	5.25
2018	4.65
2019	3.98
2020	5.89