Year	Percent
1960	42.40185
1961	48.92212
1962	36.74827
1964	43.5
1965	41.10627
1966	47.55882
1967	49.72882
1968	51.10337
1969	66.05838
1970	79.35639
1971	135.6819
1972	140.12523
1973	192.87524
1974	530.04428
1975	873.02918
1976	952.65535
1977	957.78401
1978	745.79529
1979	640.46318
1980	636.71085
1981	353.3123
1982	319.39428
1983	277.06602
1984	186.86003
1985	89.36959
1986	72.71992
1987	65.43847
1988	58.51876
1989	80.40496
1990	88.06064
1991	106.80904
1992	39.56256
1993	36.09314
1994	37.52685
1995	41.38233
1996	42.83735
1997	29.16764
1998	31.80053
1999	28.87868
2000	32.81136
2001	28.07223
2002	24.47878
2003	24.65589
2004	26.30507
2005	29.08237
2006	33.65217
2007	35.39348
2008	39.47178
2009	32.51866
2010	32.61765
2011	37.72622
2012	40.75836
2013	38.77451
2014	38.13074
2015	29.46414
2016	26.45538
2017	28.73681