Year	Percent
1960	5.31761
1961	5.21801
1962	5.1027
1963	4.95778
1964	4.79347
1965	4.61044
1966	4.42067
1967	4.24192
1968	4.09504
1969	3.98558
1970	3.87436
1971	3.76647
1972	3.68779
1973	3.58464
1974	3.46029
1975	3.07028
1976	2.93733
1977	2.81175
1978	2.70339
1979	2.34989
1980	1.96737
1981	1.86337
1982	1.75135
1983	1.70884
1984	1.75232
1985	1.82953
1986	1.98081
1987	2.04831
1988	1.81865
1989	0.88015
1990	-0.35026
1991	-1.33736
1992	-2.20332
1993	-2.75006
1994	-2.80263
1995	-2.45572
1996	-1.95741
1997	-1.53698
1998	-1.20723
1999	-1.0633
2000	-1.06455
2001	-1.05421
2002	-0.78252
2003	-0.68603
2004	-0.72584
2005	-0.80336
2006	-0.92126
2007	-1.0205
2008	-1.00584
2009	-0.83474
2010	-0.54852
2011	-0.21789
2012	0.06224
2013	0.28103
2014	0.356
2015	0.32572
2016	0.26452
2017	0.22576