Year kt 1960 0 1961 0 1962 0 1963 0 1964 0 1965 124.678 1966 187.017 1967 568.385 1968 876.413 1969 909.416 1970 825.075 1971 568.385 1972 381.368 1973 385.035 1974 839.743 1975 2225.869 1976 3894.354 1977 4968.785 1978 5298.815 1979 5669.182 1980 7253.326 1981 7898.718 1982 8756.796 1983 9207.837 1984 9299.512 1985 8958.481 1986 9442.525 1987 10791.981 1988 12273.449 1989 11030.336 1990 11122.011 1991 9515.865 1992 8379.095 1993 7832.712 1994 7715.368 1995 9446.192 1996 10711.307 1997 8474.437 1998 7165.318 1999 6153.226 2000 6714.277 2001 6274.237 2002 5507.834 2003 5727.854 2004 5709.519 2005 6420.917 2006 6644.604 2007 6893.96 2008 6673.94 2009 4950.45 2010 5269.479 2011 6024.881 2012 5614.177 2013 5493.166 2014 5412.492 2015 5944.207 2016 6153.226