Year annual % 1966 7.535663148963252 1967 6.25308215800375 1968 4.455583402951817 1969 4.776504043366202 1970 12.052075823756397 1971 2.4713317942701423 1972 2.83646033387501 1973 6.482545611262765 1974 8.80974063206179 1975 7.380428381017339 1976 6.099532359563526 1977 6.894300095225134 1978 7.429560436763467 1979 7.37064063684609 1980 4.576446964849183 1981 5.266600552824258 1982 2.002445428852056 1983 4.301603521458901 1984 5.427963147879495 1985 4.94120590442833 1986 -8.175672223830517 1987 1.2814806572456519 1988 5.5554538296742635 1989 -7.193782850798826 1990 -14.788785046728975 1991 -21.099850837939798 1992 -44.899774806083016 1993 -29.300166506887322 1994 -10.39823008849558 1995 2.5965750696933583 1996 11.202546386150146 1997 10.5208042446244 1998 3.1015096961657633 1999 2.8672956745496805 2000 1.8403811792733933 2001 4.8072986724369855 2002 5.474024887004077 2003 11.057031002010362 2004 5.792682926829258 2005 9.591138328530263 2006 9.421480811899087 2007 12.575569824640453 2008 2.4216144096064056 2009 -3.6507522959682177 2010 6.246408653033626 2011 7.934336525307799 2012 6.578831019541951 2013 5.132885312093819 2014 4.090490595817428 2015 3.3510235026535327 2016 3.4502151799687084 2017 5.159902616588269 2018 6.062036412677003 2019 5.380719265899515 2020 -6.2904717853839 2021 10.644233658096923 2022 10.95853213856239 2023 7.4744790938330254