Year	Percent
1990	3.45
1991	3.58
1992	3.76
1993	4.1
1994	4.85
1995	5.33
1996	5.78
1997	5.89
1998	5.95
1999	5.92
2000	5.6
2001	5.19
2002	4.97
2003	4.64
2004	4.29
2005	4.19
2006	4.01
2007	3.85
2008	3.8
2009	4.11
2010	4.02
2011	3.9
2012	3.89
2013	3.88
2014	3.9
2015	4.12
2016	4.06
2017	4
2018	3.92
2019	3.84