Year	Percent
1976	9.10766
1977	12.31211
1978	18.78325
1979	25.5283
1980	37.74367
1981	45.82295
1982	53.03414
1983	48.60644
1984	51.03378
1985	55.80508
1986	44.82408
1987	42.50542
1988	39.25139
1989	37.44029
1990	35.43934
1991	34.64616
1992	29.16973
1993	27.58252
1994	31.08951
1995	35.19012
1996	31.95501
1997	32.12882
1998	30.92261
1999	30.29512
2000	21.23484
2001	19.06159
2002	19.47727
2003	17.98083
2004	14.88796
2005	12.82725
2006	9.49167
2007	8.55714
2008	6.62332
2009	24.91976
2010	27.00648
2011	82.53404
2012	86.35918
2013	109.57127
2014	121.81993
2015	126.26957
2016	148.36673