Year	Percent
1974	83.33338
1980	94.91883
1981	92.00558
1982	92.07487
1983	95.65687
1984	94.78735
1985	93.46225
1987	93.01639
1988	93.45846
1989	91.19115
1990	89.30254
1991	90.78021
1993	94.08468
1998	97.41435
1999	95.0241
2000	100.6183
2002	92.77301
2003	93.47963
2004	98.13938
2005	103.74668
2006	100.03707
2007	98.20054
2008	99.29029
2009	99.93381
2010	97.55587
2011	100.29972
2012	107.26717
2013	103.9139
2014	103.90051
2015	103.37659
2016	100.56138