Year	Percent
1960	2.19884
1961	0.70108
1962	1.2115
1963	1.28134
1964	1.38514
1965	1.31208
1966	1.19953
1967	1.08896
1968	0.99381
1969	0.94887
1970	0.34572
1971	1.05951
1972	2.21908
1973	2.28928
1974	2.34329
1975	2.3192
1976	2.22949
1977	2.09977
1978	1.98778
1979	1.88102
1980	1.45438
1981	0.3819
1982	0.09968
1983	0.04906
1984	0.0231
1985	0.02835
1986	0.01092
1987	0.01072
1988	0.03836
1989	0.01738
1990	-0.30637
1991	-0.32253
1992	-0.06821
1993	-0.06813
1994	-0.13625
1995	-0.234
1996	-0.29068
1997	-0.28373
1998	-0.27102
1999	-0.27876
2000	-0.45866
2001	-0.52586
2002	-0.28498
2003	-0.12215
2004	-0.06318
2005	0.04462
2006	0.17701
2007	0.4883
2008	0.73545
2009	0.47431
2010	0.19721
2011	0.11115
2012	0.15632
2013	0.16015
2014	0.23346
2015	0.32324
2016	0.31853
2017	0.37886