Year	Percent
1960	1.26904
1961	1.55764
1962	2.31459
1963	2.39526
1964	2.23292
1965	2.07037
1966	1.52512
1967	1.53684
1968	2.01917
1969	2.07535
1970	1.95568
1971	2.26057
1972	0.65738
1973	-0.11126
1974	1.40053
1975	0.94047
1976	0.59217
1977	0.44391
1978	-0.35414
1979	0.06063
1980	0.51183
1981	0.77353
1982	1.35642
1983	1.0666
1984	0.87547
1985	0.85765
1986	0.31405
1987	-0.45254
1988	-1.13005
1989	-1.23725
1990	-0.72832
1991	-0.37105
1992	0.24264
1993	1.17713
1994	1.08953
1995	1.16583
1996	1.57099
1997	1.16971
1998	-1.01821
1999	-2.90582
2000	-3.46254
2001	-3.37707
2002	-0.00596
2003	1.93116
2004	1.59253
2005	2.41608
2006	2.43272
2007	1.83742
2008	1.11855
2009	0.51038
2010	1.12152
2011	1.27687
2012	0.69473
2013	1.01062
2014	1.23528
2015	1.21737
2016	0.97007
2017	0.7653