Year	Percent
1974	86.84201
1980	95.94302
1981	92.44917
1982	92.53112
1983	96.16167
1984	95.12285
1985	93.55132
1987	93.37115
1988	94.06113
1989	91.9126
1990	89.59048
1991	91.01892
1993	94.13698
1998	97.05824
1999	95.63529
2000	100.51882
2002	92.89437
2003	93.38986
2004	97.97831
2005	104.01434
2006	99.67848
2007	97.64803
2008	98.54096
2009	99.22581
2010	97.01314
2011	99.67389
2012	106.27178
2013	103.03302
2014	103.30368
2015	102.92999
2016	99.62638
