Year	Percent
1971	289.21802
1972	188.34012
1973	191.82991
1974	106.47193
1975	103.49768
1976	130.25807
1977	96.09799
1978	74.89289
1979	105.78432
1980	103.28959
1981	85.31552
1982	54.56541
1983	46.27828
1984	36.70994
1985	30.99309
1986	36.04489
1987	27.33176
1988	18.18172
1989	11.23418
1990	6.25436
1991	13.6081
1992	9.1753
1993	5.21526
1994	5.37543
1995	9.59769
1996	10.21135
1997	13.77934
1998	13.74354
1999	13.27808
2000	14.7812
2001	16.32813
2002	16.78531
2003	13.80651
2004	18.83261
2005	26.58139
2006	101.40715
2007	89.27262
2008	86.55446
2009	86.22774
2010	89.67692
2011	86.3727
2012	67.15043
2013	63.20975
2014	52.72207
2015	45.96121
2016	39.66078