Year	Percent
1990	5.47
1991	4.89
1992	4.05
1993	3.7
1994	3.39
1995	3.4
1996	2.5
1997	2.3
1998	2.13
1999	1.94
2000	2.29
2001	2.18
2002	2.2
2003	2.52
2004	2.05
2005	2.79
2006	3.22
2007	3.81
2008	3.86
2009	3.79
2010	4.09
2011	4.75
2012	5.3
2013	5.23
2014	5.81
2015	6.29
2016	6.14
2017	6.16
2018	6.42
2019	6.59