Year kt 1960 364554.805 1961 395067.912 1962 441924.838 1963 484088.004 1964 519272.869 1965 554124.037 1966 592726.546 1967 646279.414 1968 689073.304 1969 738185.435 1970 804345.449 1971 857212.588 1972 931021.964 1973 1000698.631 1974 1072568.164 1975 1134199.433 1976 1162270.318 1977 1204092.453 1978 1291814.427 1979 1298602.044 1980 1329591.861 1981 1345851.339 1982 1352653.624 1983 1353427.361 1984 1324021.688 1985 1336841.52 1986 1338238.647 1987 1179321.868 1988 1170165.369 1989 1154085.574 1990 1113832.915 1991 1116920.529 1992 583243.684 1993 535444.339 1994 402222.229 1995 379072.458 1996 354888.593 1997 335570.837 1998 330385.699 1999 323792.433 2000 333491.648 2001 334507.407 2002 323799.767 2003 329351.605 2004 326913.05 2005 331654.481 2006 346348.15 2007 339417.52 2008 370091.975 2009 358889.29 2010 343550.229 2011 397180.104 2012 401334.815 2013 370722.699 2014 393821.132 2015 361679.877 2016 391342.24