Year	Percent
1990	1.806
1991	2.948
1992	4.615
1993	7.645
1994	8.139
1995	7.8662
1996	8.5775
1997	9.6842
1998	8.0252
1999	6.8542
2000	4.9992
2001	4.3966
2002	4.6221
2003	5.0088
2004	6.1816
2005	7.3733
2006	7.2547
2007	6.466
2008	6.5651
2009	8.0115
2010	8.521
2011	7.763
2012	7.7109
2013	7.8877
2014	7.6936
2015	7.29
2016	6.5859
2017	6.4409