Year	Percent
1981	1.9
1983	0.8
1985	7.41
1986	7.83
1987	28.99
1988	9.35
1989	10.76
1990	7.5
1991	8.78
1993	9.17
1995	10.45
1996	8.91
1998	5.68
1999	6.12
2000	6.57
2002	4.78
2005	3.93
2006	2.65
2007	2.83
2008	2.36
2009	1.99
2010	1.417
2011	1.6261
2012	1.479
2013	1.2651
2015	0.9225
2016	0.9077