Year % 1961 3.084345021912085 1962 4.341589340542121 1963 3.4915794062692718 1964 2.8378186909815 1965 1.9231998037065436 1966 1.0284846410835227 1967 1.400162653424133 1968 2.740142284054639 1969 2.987357392469301 1970 3.2893302092621868 1971 1.4749885173918802 1972 0.1643790927569942 1973 -2.0767743656087707 1974 -4.170201382429829 1975 -1.4244145367959733 1976 1.1566470074661561 1977 1.6702643303065954 1978 2.6780834824918043 1979 2.567258501748498 1980 3.8108912380127147 1981 7.595054218052651 1982 6.418826731042974 1983 5.048162643449211 1984 8.225484220417764 1985 7.010893241333081 1986 7.164049119304354 1987 4.512987544674768 1988 6.020026082628753 1989 8.26516670894713 1990 10.362805758868975 1991 6.6766405650627965 1992 5.921223468180074 1993 4.589299084613541 1994 5.341614839810419 1995 6.241247833536359 1996 4.314937903285932 1997 3.7710592700584833 1998 6.792361779889724 1999 4.4284474226811525 2000 2.7752397905200215 2001 4.173151320435137 2002 2.9141635874535474 2003 1.3925100777027803 2004 0.7157852474095936 2005 1.2607355909186568 2006 3.1610820580593106 2007 2.7140428009846462 2008 0.7046886238081584 2009 4.833121719243554 2010 -0.237699890817205 2011 -0.23677317594109296 2012 1.7601103389448594 2013 1.2377166906658128 2014 1.0386389733822456 2015 3.6745334500242897 2016 1.9689052391642192 2017 0.12575223729818955