Year annual % 1961 4.375804375804376 1962 6.59679408138101 1963 26.234817813765183 1964 2.171721799688445 1965 3.6457399103139014 1966 -2.0205079392549647 1967 11.15428773293297 1968 8.918639758461783 1969 5.270452638873691 1970 8.374333033053842 1971 10.639726333962084 1972 15.641344236715115 1973 2.8460769615192403 1974 11.960931995432347 1975 3.5024521505143005 1976 32.49119423012412 1977 39.63097178484959 1978 31.38479322733094 1979 42.766324506167514 1980 28.710221196430407 1981 19.872598309134524 1982 25.36565881242633 1983 20.922735720867756 1984 16.016646173240062 1985 12.78859277830597 1986 4.235078125771141 1987 15.439349403796912 1988 14.862623435472308 1989 8.351303571811158 1990 19.869903410818264 1991 21.871713928214927 1992 16.803406146307506 1993 23.306427256773105 1994 19.667292569449508 1995 35.83221247621851 1996 11.260410334961573 1997 15.593722491035173 1998 13.208634568303054 1999 13.389567616550066 2000 12.864804036244015 2001 13.59213721196455 2002 13.3575243836281 2003 15.318795004551964 2004 19.61481336985248 2005 19.056802436098135 2006 17.83062851414299 2007 16.560134207562925 2008 8.45751130560778 2009 18.610061961444625 2010 15.793550639536322 2011 49.983218526845334 2012 17.6277361444479 2013 16.228533875489468 2014 14.506698090752982 2015 17.03489286527224 2016 16.186132232413676 2017 17.40450490562014 2018 11.410448936182332 2019 8.323544318361972