Year	Percent
1960	1.93793
1961	4.44311
1962	3.32032
1963	3.21986
1964	3.21908
1965	3.13986
1966	3.03672
1967	2.93564
1968	2.83596
1969	2.79895
1970	2.43569
1971	2.71503
1972	3.33619
1973	3.39752
1974	3.41776
1975	3.38995
1976	3.3532
1977	3.30284
1978	3.22054
1979	3.14913
1980	2.93324
1981	2.01908
1982	1.66316
1983	1.6077
1984	1.56073
1985	1.53596
1986	1.47404
1987	1.40243
1988	1.36672
1989	1.30954
1990	1.25904
1991	0.58773
1992	-0.07501
1993	0.27589
1994	0.28631
1995	0.1848
1996	0.10372
1997	0.07833
1998	0.02594
1999	-0.00625
2000	-0.24378
2001	-0.30758
2002	-0.30378
2003	-0.33398
2004	-0.28925
2005	-0.25977
2006	-0.26753
2007	-0.2437
2008	-0.18606
2009	-0.1411
2010	-0.40845
2011	-0.35681
2012	-0.08742
2013	-0.1508
2014	-0.1619
2015	-0.11072
2016	-0.02522
2017	0.06503