Year	Percent
1978	254.25459
1979	268.54435
1980	152.60875
1981	92.19941
1982	132.83115
1983	137.80622
1984	101.50768
1985	54.3246
1986	38.49486
1987	37.68613
1988	38.22014
1989	26.16693
1990	14.60566
1991	6.59831
1992	24.91993
1993	13.33086
1994	11.24259
1995	10.01964
1996	22.0913
1997	25.96658
1998	31.72022
1999	30.83053
2000	20.51436
2001	11.01651
2002	10.33937
2003	20.41823
2004	44.42967
2005	56.6505
2006	59.66885
2007	67.58865
2008	53.22193
2009	84.65705
2010	115.20124
2011	160.10384
2012	218.68085
2013	255.16941
2014	264.74544
2015	250.43604
2016	213.91687