Year	Percent
1960	2.21685
1961	2.97805
1962	2.80627
1963	2.78305
1964	2.75779
1965	2.51711
1966	2.13231
1967	2.13177
1968	2.29047
1969	2.13244
1970	1.95152
1971	1.90642
1972	1.92359
1973	1.93079
1974	1.95589
1975	1.8288
1976	1.64051
1977	1.58288
1978	1.51241
1979	1.13863
1980	0.84056
1981	0.81978
1982	0.87895
1983	1.00225
1984	1.03879
1985	1.05939
1986	1.13506
1987	1.26096
1988	1.25611
1989	0.63555
1990	-0.07052
1991	-0.54387
1992	-1.88242
1993	-2.04893
1994	-1.52571
1995	-1.64518
1996	-1.27193
1997	-1.06961
1998	-1.16038
1999	-1.15198
2000	-1.18849
2001	-1.46351
2002	-1.30914
2003	-1.04013
2004	-0.94389
2005	-0.93344
2006	-0.96577
2007	-0.9148
2008	-1.14818
2009	-1.68057
2010	-2.04149
2011	-1.77948
2012	-1.19909
2013	-1.02987
2014	-0.90195
2015	-0.77744
2016	-0.85358
2017	-0.88454