Year kt 1960 297.4927561818263 1961 335.8789182698038 1962 405.85369290934625 1963 435.75870186056125 1964 653.6380527908416 1965 584.6203701980197 1966 556.201324424505 1967 633.3387343811883 1968 730.7754627475249 1969 816.0326000680694 1970 941.8883742079208 1971 1047.444829938119 1972 1092.1033304393563 1973 1181.4203314418316 1974 1242.3182866707918 1975 1189.540058805693 1976 950.008101571782 1977 1372.2339244925738 1978 1234.1985593069303 1979 1441.251607085396 1980 1457.4910618131187 1981 1810.6992021410888 1982 1518.3890170420784 1983 1412.832561311881 1984 1262.6176050804454 1985 1360.0543334467818 1986 1364.1141971287125 1987 1274.7971961262372 1988 1429.0720160396038 1989 1526.5087444059404 1990 1640.1849275 1991 1534.49282 1992 1565.8089999999997 1993 1587.8109999999997 1994 1587.8109999999997 1995 1624.4809999999998 1996 1683.1529999999993 1997 1679.4859999999994 1998 1657.4839999999995 1999 1697.8209999999995 2000 1782.1619999999998 2001 2057.187 2002 1877.5039999999997 2003 2046.1859999999997 2004 2376.216000000001 2005 2108.5249999999996 2006 2240.537 2007 2273.5399999999995 2008 1965.512 2009 1939.843 2010 2306.543 2011 2200.2000000000003 2012 2167.197 2013 2460.5570000000002 2014 2841.925000000001 2015 3362.639 2016 3259.962999999999