Year	Percent
1983	8.9218
1985	8.3003
1987	5.7103
1988	6.1655
1989	5.9265
1990	4.9492
1991	4.7194
1992	3.5071
1993	4.4053
1994	5.5989
1995	5.3583
1996	4.3271
1997	3.5835
1998	2.6437
1999	2.0554
2000	1.7334
2001	1.3567
2002	1.8951
2003	2.9518
2004	3.7331
2005	3.7677
2006	2.9282
2007	2.0093
2008	1.6588
2009	2.5995
2010	3.5623
2011	3.4098
2012	4.2054
2013	5.8849
2014	5.7767
2015	4.9735
2016	3.9553
2017	3.2424