Year annual % 1961 -10.196687366616532 1962 12.721284474269288 1963 4.090577068112156 1964 14.814035087017945 1965 2.350100850817842 1966 20.68197426102131 1967 15.604093266299943 1968 24.878650127128438 1969 13.09881265767244 1970 -11.4786382537251 1971 16.075775409821556 1972 24.21650606578221 1973 32.290740614153314 1974 48.52092608513903 1975 8.75703449419953 1976 38.03782340422437 1977 21.04916921092495 1978 5.694445608130592 1979 25.844768303395526 1980 30.137675446677285 1981 11.62282172796771 1982 -6.159968224521994 1983 -18.941819560503337 1984 19.806953534391617 1985 -13.838527628561991 1986 -19.92681933691951 1987 -5.211826733364904 1988 -20.620503999269207 1989 -7.637603864865435 1990 50.32698415862756 1991 5.991209256585978 1992 4.441768875992453 1993 46.76380039332866 1994 39.101536667075976 1995 6.772149053536154 1996 12.429055075294562 1997 9.081171353734542 1998 -16.37096406632762 1999 -50.81202675348878 2000 47.00314968561256 2001 31.758946622180755 2002 36.12216213728318 2003 17.89178166702337 2004 24.36939240464311 2005 19.559997603043403 2006 12.971002324286566 2007 16.106775852490266 2008 23.9021771334509 2009 7.088880373871826 2010 16.43795052716892 2011 16.618841578245465 2012 16.95915288977775 2013 13.956723737798294 2014 14.940660271367772 2015 -4.826604284440277 2016 17.833465650972396 2017 -20.010244634336203 2018 4.676518278769989 2019 8.854971412914894 2020 9.958348707260805 2021 12.604652807399761 2022 10.12042473210735 2023 5.215589167545451