Year kt 1964 18015.061939290244 1965 18118.103284986853 1966 18971.056646586552 1967 16085.898967081539 1968 16801.20930891192 1969 16520.807654914413 1970 18472.850416635072 1971 18879.287472594504 1972 15272.87415915165 1973 16578.05231068335 1974 15690.760146264867 1975 14033.687880271855 1976 18595.350987586287 1977 16520.308747041 1978 16360.250392398384 1979 17046.214769438146 1980 18372.41256504836 1981 17789.342844564562 1982 18749.38447575211 1983 20183.73238901446 1984 20509.460799595952 1985 22606.694601059236 1986 27582.795434398275 1987 31044.927587100297 1988 32730.28894856416 1989 33118.77902510498 1990 35215.48282055323 1991 33358.72877826254 1992 35072.65558653088 1993 31427.239540253253 1994 33407.66271544898 1995 25753.48685486387 1996 27262.760968218678 1997 24288.133416765413 1998 24256.185855546384 1999 25622.168987869267 2000 25570.24565243009 2001 24915.212805351282 2002 26888.29955203989 2003 27914.7839526451 2004 31903.75336654608 2005 32155.81462339238 2006 33952.25119996364 2007 39761.66302442124 2008 33072.03728716703 2009 30415.391659453642 2010 31607.68141405995 2011 32251.837959333825 2012 26906.53892525989 2013 30059.305122004098 2014 37221.04559430376 2015 37441.09907250291 2016 42850.41366387114