Year kt 1960 0 1961 0 1962 3.667 1963 7.334 1964 7.334 1965 7.334 1966 7.334 1967 7.334 1968 11.001 1969 487.711 1970 2757.584 1971 4103.373 1972 5848.865 1973 6490.59 1974 7715.368 1975 8375.428 1976 9266.509 1977 11059.672 1978 13813.589 1979 15298.724 1980 17685.941 1981 20377.519 1982 22548.383 1983 22808.74 1984 24070.188 1985 30172.076 1986 28114.889 1987 28994.969 1988 29710.034 1989 30370.094 1990 33875.746 1991 31719.55 1992 32848.986 1993 34180.107 1994 35712.913 1995 38345.819 1996 38496.166 1997 38767.524 1998 40344.334 1999 42049.489 2000 44147.013 2001 46519.562 2002 49134.133 2003 46985.271 2004 47080.613 2005 43453.95 2006 52951.48 2007 60696.184 2008 65488.953 2009 67172.106 2010 65136.921 2011 68525.229 2012 65430.281 2013 69313.634 2014 72606.6 2015 73809.376 2016 79122.859