Year kt 1960 6930.63 1961 7223.99 1962 8338.758 1963 9101.494 1964 9816.559 1965 10190.593 1966 11441.04 1967 11496.045 1968 12845.501 1969 13344.213 1970 14411.31 1971 15295.057 1972 16299.815 1973 15434.403 1974 14836.682 1975 12889.505 1976 13762.251 1977 14095.948 1978 14557.99 1979 15434.403 1980 15456.405 1981 15764.433 1982 14114.283 1983 13611.904 1984 13699.912 1985 13256.205 1986 14132.618 1987 14627.663 1988 16314.483 1989 17935.297 1990 18540.352 1991 19130.739 1992 20835.894 1993 22838.076 1994 24253.538 1995 26857.108 1996 29280.995 1997 31077.825 1998 31235.506 1999 32181.592 2000 30652.453 2001 28488.923 2002 30348.092 2003 29611.025 2004 31349.183 2005 33853.744 2006 35764.251 2007 47263.963 2008 47590.326 2009 44968.421 2010 43494.287 2011 45665.151 2012 45199.442 2013 45951.177 2014 43853.653 2015 44389.035 2016 46101.524