Year	Percent
1974	10.24058
1975	12.56633
1976	19.17792
1977	14.16831
1978	13.74795
1979	13.51509
1980	16.96262
1981	27.38109
1982	24.86867
1983	22.17365
1984	31.16434
1985	32.67949
1986	36.05096
1987	40.44687
1988	46.20412
1990	59.55928
1994	75.33956
1998	100.15395
2000	104.56081
2001	98.05833
2002	99.41381
2003	100.29335
2004	98.33731
2005	83.88751
2006	96.1887
2007	90.75851
2008	96.42798
2009	91.52585
2010	93.67616
2011	88.57192
2012	89.85747
2013	85.00439
2014	87.82023
2015	89.09741
2016	85.34111