Year	Percent
1971	96.87452
1972	97.46989
1973	96.94503
1974	102.33551
1975	93.29413
1976	93.76828
1977	91.17985
1978	92.02788
1979	102.42054
1980	103.41517
1981	100.23919
1982	96.54852
1983	93.68314
1984	99.46344
1985	110.21694
1986	99.52626
1987	102.707
1988	102.47993
1989	101.41536
1990	99.10794
1991	89.23729
1992	87.50995
1993	85.99205
1994	88.21007
1995	87.88853
1996	90.35151
1997	94.48644
1998	93.963
1999	96.08091
2000	96.16508
2001	101.75696
2002	96.56479
2003	97.79368
2004	98.64636
2005	98.6425
2006	99.28571
2007	101.25301
2008	95.09795
2009	101.68577
2010	113.35305
2011	110.24718
2012	101.94011
2013	99.16465
2014	98.44125
2015	97.51864
2016	94.63206