Year	Percent
1960	4.74798
1961	4.71674
1962	4.79516
1963	4.76436
1964	4.77003
1965	4.76842
1966	4.81078
1967	4.81927
1968	4.7409
1969	4.534
1970	4.25884
1971	3.53065
1972	2.08044
1973	1.97754
1974	2.03621
1975	2.19319
1976	2.38682
1977	2.51369
1978	2.5428
1979	2.425
1980	2.21316
1981	1.8979
1982	1.48403
1983	1.3174
1984	1.20072
1985	1.11682
1986	1.05563
1987	0.98185
1988	0.9008
1989	0.79923
1990	0.69031
1991	0.62038
1992	0.67288
1993	0.65963
1994	0.72749
1995	-0.26864
1996	-0.03631
1997	0.15834
1998	0.27059
1999	0.25793
2000	0.15734
2001	0.03592
2002	-0.06144
2003	-0.1409
2004	-0.18708
2005	-0.15393
2006	-0.12004
2007	-0.09549
2008	-0.06267
2009	-0.01853
2010	0.03046
2011	0.08464
2012	0.1375
2013	0.19402
2014	0.25055
2015	0.30347
2016	0.36092
2017	0.41466