Year	Percent
1983	2.806
1984	2.8698
1985	3.6156
1986	1.6514
1987	3.1366
1988	2.0928
1989	2.2378
1990	2.8086
1991	2.3676
1992	1.8316
1993	1.9118
1994	3.2753
1995	1.2743
1996	2.6629
1997	1.18
1998	0.8667
2002	0.4912
2004	0.7711
2005	0.2891
2006	0.3701
2007	0.5425
2008	0.4992
2009	0.9958
2010	1.4583
2011	1.088
2012	1.4649
2013	1.6778
2014	0.9966
2015	1.444
2016	1.9286
2017	1.0508