Year annual % 1961 2.97752227586077 1962 3.15116373120966 1963 3.28525797341162 1964 3.38318215313117 1965 3.37026778402494 1966 3.34550088710455 1967 1.34293232967401 1968 -2.64665731881634 1969 -4.7871046457669 1970 1.90102763970351 1971 10.6158777263921 1972 12.1018822911535 1973 10.1787762335515 1974 5.5947552225204 1975 2.412790207134 1976 2.1125720858392 1977 1.94316502704934 1978 1.82588029336628 1979 1.83558751472411 1980 6.56405873389949 1981 12.2182963442812 1982 12.9207163632627 1983 12.2330556189807 1984 11.5757942944301 1985 10.8900440739668 1986 10.1360766759417 1987 9.32082360806009 1988 8.51148130582458 1989 7.88713230993936 1990 4.56712050094959 1991 0.623029096221364 1992 -0.360883934136508 1993 -0.374703798252124 1994 -0.350994844718984 1995 1.94209032533967 1996 9.11645322601822 1997 13.067677774177 1998 11.8978988548756 1999 10.6998565447095 2000 5.23958252727563 2001 -1.07498985987344 2002 -2.95857279553887 2003 -3.34583371838907 2004 -3.72003227551706 2005 -4.07796901122163 2006 -4.39053378535746 2007 -4.66353575517151 2008 -4.90503090271691 2009 -5.08445117030295 2010 -5.34393804525569 2011 -2.93998117935774 2012 -0.307020712378622 2013 -0.417225485626769 2014 -0.548094105534998 2015 -0.661703101237154 2016 -0.742353404784604 2017 -0.793234215651641 2018 -0.841314237571621 2019 -0.890563183033054 2020 -0.545026237308475 2021 -0.213994509732827 2022 0.141368470106524 2023 0.493221731247645