Year	Percent
1990	4.31
1992	5.46
1993	5.6
1995	5.09
1996	4.83
1997	4.65
1998	4.58
1999	4.81
2000	3.05
2001	3.99
2002	3.92
2003	3.93
2004	4.03
2005	3.68
2006	3.29
2007	3.24
2008	2.53
2009	2.43
2011	1.64
2012	1.85
2013	1.78
2014	1.63
2015	1.65
2016	1.39
2017	1.46