Year	Percent
1976	16.64032
1977	14.78488
1978	17.5426
1979	9.55476
1980	13.76019
1981	18.96437
1982	25.18655
1983	30.05094
1984	40.03563
1985	32.50584
1986	26.94163
1987	25.41092
1988	29.027
1989	32.77747
1990	37.18134
1991	27.18726
1992	28.36398
1993	28.95666
1994	30.84537
1995	20.77718
1996	16.34268
1997	20.51645
1998	14.75858
1999	9.68134
2000	12.87689
2001	12.70255
2002	15.09825
2003	7.80278
2004	8.8345
2005	8.43605
2006	7.09726
2007	19.36052
2008	15.5562
2009	11.73668
2010	13.31356
2011	16.04361
2012	7.05037
2013	19.71221
2014	13.00696
2015	11.28539
2016	49.11507