Year	Percent
1970	65.018
1977	88.7763
1978	87.17402
1979	86.85711
1980	83.53767
1981	82.87441
1993	89.28469
1995	89.26692
1998	99.47228
1999	104.04171
2000	102.81455
2001	98.18262
2002	97.64314
2003	102.42444
2004	102.61738
2005	102.46245
2006	103.22991
2007	105.20039
2008	103.83924
2009	100.7373
2010	101.96055
2011	98.80071
2012	93.62278
2013	94.51414
2014	95.18702
2015	99.00133
2016	102.51263