Year	Percent
1990	5.3
1991	5.22
1992	5.18
1993	4.72
1994	5.27
1995	5.53
1996	5.56
1997	5.89
1998	5.93
1999	5.78
2000	6.06
2001	6.14
2002	6.42
2003	6.32
2004	6.55
2005	7.41
2006	7.86
2007	8.85
2008	9.37
2009	10.23
2010	10.79
2011	11.19
2012	11.99
2013	12.1
2014	12.38
2015	12.26
2016	12.63
2017	13
2018	13.98
2019	14.72