Year	Percent
1960	1.27255
1961	1.26737
1962	1.28229
1963	1.32307
1964	1.39199
1965	1.47341
1966	1.58011
1967	1.66422
1968	1.65534
1969	1.52762
1970	1.3254
1971	1.08205
1972	0.8834
1973	0.79661
1974	0.86712
1975	1.03764
1976	1.24249
1977	1.38809
1978	1.42779
1979	1.32427
1980	1.12248
1981	0.89676
1982	0.70382
1983	0.54331
1984	0.43245
1985	0.35991
1986	0.30254
1987	0.238
1988	0.16245
1989	0.06798
1990	-0.03216
1991	-0.14668
1992	-0.2332
1993	-0.23314
1994	-0.11725
1995	0.07813
1996	0.31168
1997	0.5092
1998	0.62109
1999	0.61128
2000	0.51365
2001	0.39351
2002	0.29748
2003	0.21929
2004	0.17618
2005	0.15666
2006	0.13935
2007	0.11205
2008	0.09291
2009	0.08292
2010	0.07952
2011	0.07936
2012	0.07973
2013	0.08208
2014	0.08456
2015	0.08723
2016	0.09124
2017	0.09384