Year	Percent
1970	18.99002
1971	21.225
1972	27.20211
1973	31.57215
1974	34.8667
1975	42.24218
1976	58.41453
1977	69.26785
1978	79.68567
1979	79.67658
1980	72.25069
1981	73.33741
1982	73.23443
1983	75.73642
1984	75.35455
1985	75.05075
1986	77.40868
1987	79.88889
1988	104.57453
1989	111.1007
1990	107.45943
1991	102.93521
1992	84.67708
1993	81.38055
1994	77.26193
1995	67.89906
1996	63.3087
1997	58.72817
1998	57.77935
1999	59.9095
2000	55.89859
2001	65.354
2002	61.99558
2003	63.16957
2004	59.56009
2005	56.52001
2006	55.91862
2007	47.61061
2008	190.47711
2009	180.74357
2010	183.03969
2011	175.04249
2012	162.75528
2013	162.01797
2014	167.35263
2015	185.08198
2016	177.82488