Year annual % 1961 7.112375533428166 1962 15.405046480743692 1963 27.387802071346375 1964 -5.239385727190606 1965 18.875119161105815 1966 19.406575781876505 1967 21.356615177971793 1968 14.277808522412839 1969 -4.842615012106537 1970 30.432569974554706 1971 17.908700741318768 1972 30.0132362673726 1973 13.133112751336217 1974 19.41507311586052 1975 21.721929163526752 1976 6.887478718464633 1977 15.884737909064581 1978 19.292765213045108 1979 23.138158583848327 1980 25.119088125212656 1981 18.933985994969067 1982 12.587172744941121 1983 2.1171811535337124 1984 7.3136777208770445 1985 5.1751297257227575 1986 5.546011188934409 1987 -3.4641068447412353 1988 -26.88715953307393 1989 -2.063745491100467 1990 36.650163023789396 1991 32.18076175326971 1992 25.565140071167953 1993 18.939701301812953 1994 15.756070417831689 1995 8.366831532786986 1996 7.309075925669513 1997 13.736690592081583 1998 15.523948363904244 1999 8.464688316468102 2000 9.266503599853344 2001 7.889808232853043 2002 -1.70735763421427 2003 3.5214049708729864 2004 8.045417041477771 2005 8.566959701376254 2006 22.27703459448542 2007 16.00060252764456 2008 14.583178193579528