Year	Percent
1976	2.83895
1977	0.96889
1978	1.31328
1979	2.15108
1980	3.86695
1981	4.43542
1982	4.65776
1983	5.89386
1984	6.91822
1985	10.51993
1986	8.41047
1987	13.36924
1988	12.9893
1989	18.49823
1990	14.25781
1991	16.44527
1992	20.39602
1993	20.47134
1994	8.29619
1995	20.48618
1996	19.80544
1997	14.57855
1998	17.13088
1999	27.30876
2000	25.72983
2001	11.83949
2002	14.49782
2003	15.3483
2004	12.95881
2005	10.85402
2006	6.72997
2007	4.9902
2008	2.0047
2009	1.90379
2010	2.07891
2011	1.92269
2012	2.00691
2013	3.04783
2014	4.20341
2015	7.1472
2016	8.28671