Year kt 1960 22313.577322335594 1961 26803.095882685393 1962 33105.76504686392 1963 34903.149123702824 1964 39940.554496948695 1965 44627.15464467118 1966 48411.12112222676 1967 53645.60808284532 1968 55494.233372401126 1969 56108.735104804204 1970 63774.25030516569 1971 65310.50463617339 1972 69493.59105578718 1973 77989.7468063587 1974 80770.59333389855 1975 81597.75731517814 1976 81050.25353709309 1977 87415.47731684438 1978 98074.07604704674 1979 113971.37999201963 1980 124177.0079705689 1981 127686.54657685503 1982 138996.20769539714 1983 145761.5272642186 1984 152117.30478696473 1985 156351.53841322023 1986 155291.99530116186 1987 163517.24860660365 1988 172478.4456288481 1989 216422.550130553 1990 183820.6370289837 1991 191361.10848028824 1992 168527.1756199182 1993 182911.53008469802 1994 199834.3000432625 1995 218315.53904917385 1996 242381.2921414115 1997 258190.3077050286 1998 285597.4567529795 1999 294059.6911253895 2000 294957.4991462873 2001 307613.4420373649 2002 319792.6048261358 2003 338023.9412994656 2004 368753.03318517614 2005 377443.4939371977 2006 407638.03011857776 2007 407284.2800201237 2008 418899.0749193658 2009 417857.477407251 2010 451212.1811348207 2011 449070.0837409542 2012 472472.0064622037 2013 484896.17134662915 2014 497650.49436148553 2015 508887.6621579337 2016 505426.9369413256