Year annual % 1961 0.2016129032256475 1962 30.583501006036357 1963 6.0606060606064345 1964 11.573849878934212 1965 0.3472222222223712 1966 17.34429065743964 1967 8.182823442683196 1968 19.717206132879202 1969 18.77223439678942 1970 11.530443533894088 1971 12.864969384466615 1972 9.831915177126845 1973 22.409788900828488 1974 34.87851843461517 1975 12.577942936323169 1976 25.087650591175052 1977 38.12551714884175 1978 15.43331138622964 1979 22.546998237419725 1980 21.386632686928813 1981 28.56415494617867 1982 19.01314969234288 1983 26.53697153444494 1984 20.59591737348313 1985 17.398953561780115 1986 -4.267346054269967 1987 -18.327903801470814 1988 2.0414627672445684 1989 2.451950486603577 1990 -0.7096125442984835 1991 1.4786711484247594 1992 -16.720465084088865 1993 -9.228409066355523 1994 26.54093347737718 1995 -6.154587470589426 1996 -10.101226591832486 1997 18.5776472727148 1998 7.773653789408518 1999 13.296899304917117 2000 19.133700165252055 2001 1.3747843509647653 2002 21.173582236974394 2003 1.94742014185132 2004 7.450716034796528 2005 5.6541436945834285 2006 8.127912580107974 2007 14.871853252358827 2008 13.951304112797875 2009 8.231522312772151 2010 13.807833210973655 2011 10.130373106665404 2012 -0.058902576158991055 2013 11.445279440033767 2014 13.24323670217811 2015 8.80292225458133 2016 5.0009874351531165 2017 5.432283213760257 2018 13.937856346299968