Year	Percent
1970	26.35459
1971	22.86
1972	28.85996
1973	30.91031
1974	25.39209
1975	25.84815
1976	25.89111
1977	33.56265
1978	34.992
1979	31.99992
1980	31.59177
1981	36.55608
1982	36.87074
1983	41.43547
1984	44.97814
1985	50.99378
1986	49.39735
1987	67.11308
1988	61.79805
1989	66.2742
1990	67.18171
1991	67.64867
1992	71.4691
1993	83.47433
1994	102.54262
1995	93.7425
1996	94.87135
1997	93.92985
1998	95.08754
1999	94.02082
2000	139.43883
2001	131.76921
2002	126.56009
2003	111.16277
2004	83.37633
2005	69.18597
2006	18.23117
2007	20.4775
2008	19.22426
2009	28.53134
2010	28.80465
2011	29.27916
2012	32.24644
2013	35.7912
2014	49.7612
2015	56.66028
2016	51.80756