Year annual % 1961 2.785406041584935 1962 11.221374045801527 1963 5.284831846259437 1964 25.4367666232073 1965 13.332813636836088 1966 6.2340937750773815 1967 1.8345059783312472 1968 11.213546965072906 1969 15.26250595521677 1970 5.768467693935586 1971 1.8054491738702265 1972 16.063751381894118 1973 29.886228337081626 1974 15.564111182408002 1975 9.633181153161411 1976 12.778956846099426 1977 17.747776003649633 1978 12.688121269356966 1979 13.239141529452848 1980 4.203255388089511 1981 11.009383152211027 1982 10.297296078021253 1983 14.456066245505486 1984 9.737603836045443 1985 17.127454550298854 1986 11.390990936342083 1987 5.631770263708437 1988 11.075453135538972 1989 15.572990597454234 1990 19.87413427573663 1991 15.92659336425677 1992 15.218124239906562 1993 8.78209797517962 1994 23.17488555912733 1995 9.030010105775657 1996 9.04520467012558 1997 19.825046531015385 1998 -1.0934242347628986 1999 13.705356494560897 2000 13.073874936875995 2001 9.675750659750621 2002 15.9341278120192 2003 12.437923800967459 2004 19.264471745145638 2005 18.591896416289455 2006 19.99365997700181 2007 22.21259981515115 2008 23.389689818504095