Year	Percent
1990	2.28
1991	2.23
1992	2.21
1993	2.21
1994	2.14
1995	2.07
1996	2.07
1997	2.06
1998	2.01
1999	2
2000	1.95
2001	2.71
2002	2.68
2003	1.99
2004	1.73
2005	1.89
2006	1.82
2007	1.59
2008	1.67
2009	2.82
2010	3.58
2011	3.43
2012	3.85
2013	4.27
2014	5.33
2015	5.06
2016	4.4
2017	4.39
2018	4.69
2019	6.34