Year	Percent
1960	2.63976
1961	2.57325
1962	2.46284
1963	2.37334
1964	2.35692
1965	2.29511
1966	2.24177
1967	2.1487
1968	1.88763
1969	1.43447
1970	1.01686
1971	1.24248
1972	1.88607
1973	1.92075
1974	1.75546
1975	1.67066
1976	1.37626
1977	1.11624
1978	1.14425
1979	1.33247
1980	1.40537
1981	1.44906
1982	1.63805
1983	1.61829
1984	1.35207
1985	1.068
1986	1.00728
1987	1.36328
1988	1.82904
1989	1.49301
1990	1.02707
1991	1.35934
1992	1.45427
1993	1.20895
1994	1.0561
1995	0.72812
1996	0.72205
1997	0.99641
1998	1.24597
1999	1.36749
2000	1.51428
2001	1.47121
2002	1.033
2003	0.82943
2004	1.01256
2005	1.7149
2006	2.47852
2007	2.658
2008	1.98483
2009	0.46544
2010	-0.07658
2011	0.31938
2012	0.54581
2013	0.98121
2014	1.14891
2015	1.07716
2016	1.4254
2017	1.76786