Year	Percent
1970	73.07826
1971	70.12588
1972	57.00605
1973	64.97237
1974	59.66626
1975	56.59434
1976	50.80067
1977	54.05628
1978	56.87627
1979	77.64783
1980	78.89933
1981	83.42467
1982	92.84235
1983	105.11707
1984	173.72951
1985	226.45247
1986	172.10109
1987	162.48295
1988	133.07614
1989	115.12811
1990	115.22902
1991	126.35003
1992	143.45617
1993	94.69699
1994	99.61603
1995	83.48964
1996	64.35258
1997	52.26402
1998	46.95561
1999	47.62807
2000	56.23102
2001	63.49247
2002	61.7062
2003	64.77745
2004	68.4807
2005	62.93815
2006	71.91967
2007	86.58366
2008	79.6151
2009	97.82458
2010	111.70797
2011	102.50943
2012	97.98657
2013	92.88573
2014	103.51491
2015	102.0762
2016	104.16192