Year	Percent
1974	7.74194
1975	11.2687
1977	13.0117
1978	13.97719
1979	12.03349
1980	18.99625
1981	29.63733
1982	25.89096
1983	24.8191
1984	32.50492
1985	34.95219
1986	36.53108
1987	40.92518
1988	46.51914
1990	60.32172
1994	77.14045
1998	98.01358
2000	102.34674
2001	96.52734
2002	98.39824
2003	97.81618
2004	97.57404
2005	80.22832
2006	92.506
2007	87.98241
2008	93.75516
2009	91.39084
2010	94.4604
2011	87.27366
2012	90.37664
2013	85.80904
2014	90.30666
2015	88.76844
2016	85.90041