Year	Percent
1970	6.92554
1971	11.27608
1972	9.55196
1973	12.62473
1974	7.84213
1975	6.21681
1976	3.77134
1977	8.82216
1978	13.99437
1979	13.298
1980	14.63386
1981	19.23268
1982	23.82957
1983	50.54493
1984	64.16125
1985	66.98344
1986	115.12296
1987	133.76529
1988	130.14871
1989	136.02076
1990	120.05397
1991	134.44809
1992	110.12182
1993	228.37172
1994	210.33454
1995	129.50684
1996	95.90211
1997	84.75968
1998	103.89183
1999	84.59212
2000	80.45663
2001	78.46167
2002	59.94053
2003	61.18994
2004	51.1596
2005	26.04605
2006	6.83115
2007	7.8553
2008	6.80571
2009	10.29062
2010	4.42972
2011	4.53966
2012	4.13098
2013	4.31993
2014	4.51211
2015	6.15377
2016	7.85913