Year kt 1960 0 1961 0 1962 0 1963 0 1964 0 1965 0 1966 0 1967 0 1968 0 1969 0 1970 0 1971 0 1972 0 1973 0 1974 0 1975 0 1976 0 1977 0 1978 0 1979 0 1980 0 1981 0 1982 0 1983 0 1984 0 1985 0 1986 0 1987 0 1988 0 1989 0 1990 0 1991 0 1992 0 1993 0 1994 0 1995 0 1996 0 1997 0 1998 0 1999 0 2000 0 2001 0 2002 0 2003 568.385 2004 238.355 2005 473.043 2006 590.387 2007 1004.758 2008 927.751 2009 993.757 2010 1496.136 2011 1679.486 2012 1991.181 2013 2038.852 2014 2005.849 2015 2027.851 2016 1914.174