Year	Percent
1990	4.1
1991	4.29
1992	4.46
1993	4.23
1994	4.01
1995	3.81
1996	3.61
1997	3.43
1998	3.26
1999	3.09
2000	2.93
2001	2.69
2002	3.18
2003	4.25
2004	3.49
2005	2.52
2006	2.74
2007	3.09
2008	3.8
2009	3.38
2010	3
2011	2.89
2012	2.94
2013	3.48
2014	4.03
2015	4.22
2016	4.41
2017	5.43
2018	5.83
2019	6.67