Year	Percent
1960	2.49644
1961	2.42863
1962	2.18806
1963	-0.3874
1964	-0.75545
1965	0.56374
1966	0.43289
1967	-1.28648
1968	-5.3359
1969	-6.09448
1970	-2.94727
1971	-5.31487
1972	-2.78756
1973	-7.72758
1974	-4.12322
1975	-3.60059
1976	-5.76275
1977	-6.19895
1978	-10.6282
1979	-7.69522
1980	-14.45785
1981	-19.78792
1982	-14.25313
1983	-16.59817
1984	-15.20874
1985	-11.39835
1986	-8.09112
1987	-7.70801
1988	-7.30257
1989	-6.44481
1990	-6.77507
1991	-7.82502
1992	-8.39274
1993	-9.10825
1994	-7.31321
1995	-6.46111
1996	-5.78058
1997	-6.23721
1998	-6.56571
1999	-6.9977
2000	-9.29167
2001	-9.038
2002	-10.41637
2003	-12.11361
2004	-12.63004
2005	-15.40678
2006	-17.47121
2007	-22.39894
2008	-26.30121
2009	-16.88058
2010	-15.38834
2011	-18.31446
2012	-20.99484
2013	-20.8177
2014	-19.17779
2015	-16.8162
2016	-14.96258
2017	-15.71847