Year	Percent
1974	1.52195
1975	4.23546
1976	7.62115
1977	16.82308
1978	18.28863
1979	23.83881
1983	36.40357
1984	42.65456
1985	41.83551
1986	45.46317
1987	48.03032
1988	54.76463
1989	61.92285
1990	65.07015
1992	73.89675
1994	71.75537
1995	74.24564
1996	76.87855
1997	79.30246
1998	81.52995
1999	83.85644
2000	82.94362
2001	84.4149
2002	87.4705
2003	89.46701
2009	96.07333
2011	97.08152
2012	101.11443
2013	96.25046
2014	104.47761
2015	100.50253
2016	104.0378