Year kt 1960 1130683.060303155 1961 1233950.46538227 1962 1400584.4911998326 1963 1565199.8445618576 1964 1736678.6842727093 1965 1896065.1836157588 1966 2076613.2786024634 1967 2243429.4773001596 1968 2434272.801810104 1969 2642304.3837402435 1970 2951112.033523884 1971 3120252.1673411257 1972 3378425.6036302675 1973 3611562.577879391 1974 3613088.8911994332 1975 3576910.3419231214 1976 3770107.1431007395 1977 3800958.366530975 1978 4014066.171148088 1979 4068225.6760527426 1980 3964008.017842119 1981 3806625.4201805433 1982 3735740.4754430577 1983 3669321.2280645296 1984 3635220.434340016 1985 3605176.6798919966 1986 3639572.8890978084 1987 3453121.408076497 1988 3431930.270884711 1989 3487079.4176517166 1990 3336304.279588509 1991 3350673.8888738393 1992 2713494.1103829746 1993 2602736.3042752147 1994 2402866.1686466406 1995 2394838.364135673 1996 2388012.88057681 1997 2336904.9914897094 1998 2362379.3978779656 1999 2310779.4820627742 2000 2273233.7733154 2001 2326912.77951546 2002 2312200.0705107986 2003 2323942.121901492 2004 2327156.9431549637 2005 2307427.781193219 2006 2316737.7123365197 2007 2256545.2864822573 2008 2276640.0532306004 2009 2173319.331913513 2010 2144583.4284371943 2011 2131950.6478674132 2012 2071526.2956885863 2013 2024913.5387780538 2014 2024410.4309472232 2015 2163011.0032665655 2016 2233132.6596480464