Year	Percent
1974	2.30361
1975	7.60115
1976	12.25577
1978	28.54296
1979	35.11164
1983	49.0327
1984	55.4533
1985	53.34867
1986	54.65374
1987	56.70839
1988	62.59881
1989	69.19319
1990	67.94086
1992	77.93693
1994	72.57699
1995	74.8427
1996	76.64801
1997	77.91879
1998	80.75599
1999	83.4146
2000	83.80925
2001	84.15468
2002	89.03008
2003	91.32396
2009	98.27734
2011	95.59043
2012	101.34727
2013	94.796
2014	103.51061
2015	100.19262
2016	104.03269