Year	Percent
1970	36.09467
1971	53.92644
1972	55.02698
1973	58.45493
1974	59.34663
1982	72.68188
1983	76.26002
1984	76.16845
1985	70.5637
1986	68.70983
1987	72.55093
1988	71.71733
1989	71.12568
1990	83.00056
1991	73.78233
1992	84.9299
1993	82.9782
1994	81.51694
1995	85.89171
1996	87.41151
1998	94.53358
1999	96.89246
2000	97.49033
2002	96.51466
2004	105.76288
2005	110.53584
2006	117.87097
2007	121.02951
2008	121.02903
2009	126.26277
2010	123.93036
2011	119.78469
2012	112.54636
2013	101.29706
2014	99.87075
2015	99.75065
2016	100.71159