Year	Percent
1971	71.82426
1972	66.85484
1973	63.1769
1974	59.82265
1975	63.63636
1976	76.19363
1977	75.67568
1978	89.546
1979	85.47718
1980	83.51585
1981	79.23118
1982	90.40881
1984	86.35965
1985	82.18639
1986	75.38518
1987	64.53877
1988	70.59006
1989	70.88532
1990	71.23209
1991	74.12625
1992	63.19797
1993	63.07692
1994	62.97641
1995	55.2
1996	47.65474
1998	87.17728
1999	92.8723
2003	105.30533
2005	92.7565
2006	85.86314
2007	104.0014
2008	108.97209
2009	102.95455
2011	99.15671
2013	94.40543
2014	87.51609
2015	90.41431
2016	94.19505