Year	Percent
1970	33.96051
1971	38.74701
1972	43.77647
1973	50.00308
1974	48.41394
1975	59.20379
1976	56.48762
1977	64.65856
1978	78.30853
1979	116.20192
1980	110.27117
1981	112.86525
1982	131.72781
1983	163.71306
1984	168.00506
1985	233.80373
1986	244.51792
1987	211.24435
1988	389.23718
1989	1233.09931
1990	1111.26937
1991	960.37591
1992	879.24056
1993	879.95921
1994	366.08176
1995	280.94246
1996	154.97604
1997	153.23615
1998	143.35894
1999	137.57137
2000	139.07623
2001	125.64548
2002	128.30274
2003	133.70966
2004	90.83578
2005	81.0201
2006	63.88033
2007	56.81327
2008	56.93529
2009	73.26553
2010	82.26615
2011	83.62626
2012	54.16155
2013	91.14669
2014	87.71244
2015	85.03692
2016	85.35147