Year kt 1960 977329.1501584342 1961 1032102.791188866 1962 1133989.0069774913 1963 1228043.3355017789 1964 1351789.3091867827 1965 1442574.0434289747 1966 1570350.2620620755 1967 1677850.9952918652 1968 1821862.343908427 1969 1992215.183497353 1970 2080090.8056813304 1971 2236653.967870605 1972 2355740.026423213 1973 2434154.2595751393 1974 2464995.9706908762 1975 2473148.5997170913 1976 2618571.2833733913 1977 2661513.395100198 1978 2799389.432402401 1979 2949966.8360080956 1980 3037974.1240506186 1981 3090164.415425516 1982 3029263.8575882013 1983 3075650.5353827486 1984 3330154.249041112 1985 3472327.7429223615 1986 3411783.936068133 1987 3690359.639228792 1988 3885823.2526614326 1989 4082069.6521838773 1990 4237095.42630304 1991 4394438.364913461 1992 4045055.412608612 1993 4151669.877433084 1994 4159146.164575398 1995 4280835.927497054 1996 4450212.670386963 1997 4464488.337314664 1998 4493665.635987141 1999 4706483.315294552 2000 4838354.206114128 2001 4867044.322709768 2002 5001784.1484542005 2003 5200906.139501222 2004 5348647.1701209815 2005 5509524.737963432 2006 5634269.973967368 2007 5855245.027410821 2008 6011683.525302914 2009 5902905.449358245 2010 6362935.097041102 2011 6496773.560355891 2012 6603953.622238413 2013 6711986.180879339 2014 6774278.0073348405 2015 7146572.79793599 2016 7322549.21730787