Year	Percent
1971	117.97811
1972	107.97214
1973	143.33827
1974	145.26673
1975	80.26353
1976	96.86884
1977	89.65859
1978	88.08558
1979	101.00909
1980	87.05553
1981	54.73219
1982	36.1872
1983	26.61867
1984	23.70445
1985	28.00275
1986	31.72382
1987	37.53217
1988	40.33847
1989	53.64511
1990	69.53
1991	68.59575
1992	90.03808
1993	107.78017
1994	86.82414
1995	71.91878
1996	70.30405
1997	45.46049
1998	61.8632
1999	73.68592
2000	68.30414
2001	66.09201
2002	69.83686
2003	87.27023
2004	109.72237
2005	108.54523
2006	118.30865
2007	121.11175
2008	86.22067
2009	80.84856
2010	79.61769
2011	92.18297
2012	72.07076
2013	71.42872
2014	58.98593
2015	49.89874
2016	47.15474