Year % of output 1971 7.8542485907806405 1972 7.114661403461979 1973 7.2975367276127665 1974 7.441388613281903 1975 7.5016362106400445 1976 7.398256811474847 1977 7.347928621213133 1978 8.222566829124208 1979 8.016470772197753 1980 8.091670267493905 1981 7.63263389793781 1982 7.802150597234155 1983 8.241301265270506 1984 6.734153287485543 1985 6.751626256652868 1986 5.066041511807421 1987 5.949911910974332 1988 5.6240476520293665 1989 5.992729522778251 1990 6.8014936850093735 1991 7.386060570141646 1992 8.261470246437602 1993 7.723381744734058 1994 8.238042829428444 1995 6.8501062644111235 1996 8.029657405829214 1997 8.303373694958152 1998 8.843838128333273 1999 8.834761702266855 2000 8.887529459744558 2001 8.90628964181101 2002 7.822465849669017 2003 9.069003439314658 2004 10.813462270006207 2005 9.630202580683223 2006 9.772202880527244 2007 9.737485386332235 2008 10.294113120430936 2009 11.256563286775465 2010 10.960642115765491 2011 10.528081398571208 2012 10.276608080961891 2013 10.393182381097754 2014 10.594765610655216