Year	Percent
1971	1116.70741
1972	870.83125
1973	657.19114
1974	528.3355
1975	335.06164
1976	292.56611
1977	160.53506
1978	158.17823
1979	160.75997
1980	132.95508
1981	94.09649
1982	76.05668
1983	42.22489
1984	27.34095
1985	17.87968
1986	19.61108
1987	25.49917
1988	24.26845
1989	20.12272
1990	21.76592
1991	25.54661
1992	28.82435
1993	34.93797
1994	32.4141
1995	26.78636
1996	26.17772
1997	27.78468
1998	29.97101
1999	29.34576
2000	34.30769
2001	39.36522
2002	35.65051
2003	39.98841
2004	45.38239
2005	49.04875
2006	56.85153
2007	55.71285
2008	66.47285
2009	74.62004
2010	79.25393
2011	96.7151
2012	104.65452
2013	135.40384
2014	149.21318
2015	196.80491
2016	205.45649