Year	Percent
1960	4.64019
1961	5.33665
1962	5.65404
1963	5.50453
1964	5.07193
1965	4.27111
1966	3.30708
1967	2.82505
1968	2.17188
1969	2.12571
1970	1.94302
1971	1.84555
1972	1.88628
1973	1.76397
1974	1.57575
1975	1.36754
1976	1.15348
1977	1.14033
1978	1.05908
1979	1.1968
1980	1.22272
1981	1.37933
1982	1.63306
1983	1.75973
1984	1.90434
1985	2.07697
1986	2.17847
1987	2.37783
1988	2.3226
1989	2.24754
1990	2.21998
1991	2.08622
1992	2.09598
1993	1.79605
1994	1.40991
1995	1.12984
1996	0.60006
1997	0.2788
1998	-0.10944
1999	-0.05974
2000	-0.02988
2001	0.14934
2002	0.27816
2003	0.2576
2004	0.19771
2005	-0.11858
2006	-0.42606
2007	-0.68749
2008	-0.55141
2009	-0.02011
2010	0.80121
2011	0.31869
2012	2.18341
2013	5.13857
2014	9.10923
2015	5.11456
2016	4.49849
2017	4.49548