Year kt 1960 0 1961 451.041 1962 689.396 1963 605.055 1964 1191.775 1965 1778.495 1966 1851.835 1967 1793.163 1968 1884.838 1969 2478.892 1970 135.679 1971 674.728 1972 3138.952 1973 3149.953 1974 2453.223 1975 4462.739 1976 6068.885 1977 3608.328 1978 23875.837 1979 8173.743 1980 25500.318 1981 11173.349 1982 7176.319 1983 16622.511 1984 30535.109 1985 27722.52 1986 33113.01 1987 40149.983 1988 39005.879 1989 36703.003 1990 38939.873 1991 38459.496 1992 31957.905 1993 36127.284 1994 37418.068 1995 47260.296 1996 50608.267 1997 39038.882 1998 54685.971 1999 50963.966 2000 39742.946 2001 41063.066 2002 44689.729 2003 44062.672 2004 41242.749 2005 61260.902 2006 49346.819 2007 51117.98 2008 51591.023 2009 54938.994 2010 53409.855 2011 56768.827 2012 64168.833 2013 65503.621 2014 73893.717 2015 78833.166 2016 78741.491