Year	Percent
1990	1.7
1991	11.1
1992	15.3
1993	16.4
1994	12.8
1995	11.1
1996	12.5
1997	13.7
1998	12.2
1999	14.1
2000	16.22
2001	19.92
2002	18.11
2003	13.73
2004	12.04
2005	10.08
2006	8.95
2007	6.88
2008	5.61
2009	6.82
2010	10.28
2011	11.26
2012	12.27
2013	12.94
2014	11.42
2015	9.14
2016	7.57
2017	6.16
2018	5.21
2019	4.23
2020	5.12