Year	Percent
1960	4.72529
1961	5.39053
1962	2.02027
1963	12.85189
1964	2.48152
1965	6.40789
1966	6.02189
1967	6.08792
1968	12.61211
1969	7.9352
1970	5.13298
1971	11.11303
1972	7.31298
1973	9.73343
1974	6.68977
1975	4.92766
1976	1.76454
1977	-3.1296
1978	2.88284
1979	0.26443
1980	3.52709
1981	0.21756
1982	0.21509
1983	0.27942
1984	0.25081
1985	0.15892
1986	0.08135
1987	0.05849
1988	0.05053
1989	0.08812
1990	2.85087
1991	0.80855
1992	0.85979
1993	0.81587
1994	0.69193
1995	0.46482
1996	0.25658
1997	0.24209
1998	0.16598
1999	0.05711
2000	0.03959
2001	-0.08564
2002	-0.03593
2003	-0.00369
2004	-0.03595
2005	-0.01199
2006	-0.07656
2007	-0.02953
2008	0.05537
2009	0.00553
2010	-0.04337
2011	-0.06093
2012	-0.09331
2013	-0.13596
2014	-0.1482
2015	-0.16141
2016	-0.18586
2017	-0.22535