Year	Percent
1971	94.3051
1972	91.14548
1973	92.15502
1974	91.1041
1981	93.18063
1982	91.24505
1983	91.78896
1984	98.16935
1985	99.48283
1986	97.22662
1987	98.36417
1988	101.73979
1989	98.17269
1990	95.08431
1991	97.51313
1992	96.75833
1993	99.0001
1994	96.35431
1998	101.46174
1999	101.53588
2000	100.38834
2001	101.19987
2002	104.86837
2004	100.39352
2005	100.31082
2006	101.81723
2007	101.52842
2008	100.59383
2009	97.73934
2010	98.88476
2011	99.57378
2012	97.56382
2013	98.59555
2014	98.34991
2015	99.15556
2016	105.05821