Year	Percent
1960	2.15198
1961	1.57317
1962	1.00771
1963	0.55836
1964	0.29308
1965	0.19777
1966	0.09874
1967	-0.0558
1968	0.05151
1969	0.18006
1970	0.58937
1971	0.99992
1972	1.3858
1973	1.60036
1974	1.60737
1975	1.4471
1976	1.28551
1977	1.11433
1978	1.07138
1979	1.17375
1980	1.31729
1981	1.5545
1982	1.67924
1983	1.69067
1984	1.47334
1985	1.12649
1986	0.71187
1987	0.45007
1988	0.21573
1989	0.26304
1990	0.43233
1991	0.62645
1992	0.80354
1993	0.91666
1994	0.95435
1995	0.86391
1996	0.89527
1997	0.91293
1998	0.86661
1999	0.87489
2000	0.88288
2001	0.8628
2002	0.82784
2003	0.92737
2004	1.15025
2005	1.4276
2006	1.80354
2007	2.02254
2008	2.09128
2009	1.88161
2010	1.52119
2011	1.08057
2012	0.75983
2013	0.49634
2014	0.42311
2015	0.45788
2016	0.49996
2017	0.50781