Year	Percent
1970	96.80851
1971	96.83955
1972	97.02572
1973	97.12919
1974	97.22882
1975	97.32704
1976	97.5
1977	97.59317
1978	97.6834
1979	97.84781
1980	97.9342
1981	98.17073
1982	98.25361
1983	98.4103
1984	98.56604
1985	98.71988
1986	98.94737
1987	99.02476
1988	99.25037
1989	99.32635
1990	99.47644
1991	99.70082
1992	99.85052
1993	100
1994	100.14948
1995	100.29895
1996	100.4481
1997	100.67164
1998	100.89419
1999	101.04089
2000	101.18694
2001	101.40637
2002	101.54982
2003	101.69118
2004	101.90476
2005	102.0423
2006	102.1045
2007	102.31047
2008	102.44078
2009	102.56959
2010	102.69504
2011	102.81889
2012	102.86914
2013	102.98819
2014	103.10559
2015	103.15068