Year	Percent
1983	6.1372
1984	4.091
1985	5.7861
1986	4.131
1987	6.0786
1988	5.1958
1989	6.1245
1990	5.1328
1991	7.874
1992	7.2527
1993	8.1065
1994	6.3223
1995	6.9188
1996	5.9513
1997	4.4446
1998	4.2253
1999	3.2179
2000	3.9438
2001	3.9904
2002	5.0269
2003	3.9967
2004	5.4897
2005	4.6351
2006	3.5437
2007	2.9898
2008	2.4326
2009	4.7354
2010	6.6942
2011	6.621
2012	5.6501
2013	5.2043
2014	5.0539
2015	3.987
2016	3.9603
2017	3.8283