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 157.681 1986 414.371 1987 553.717 1988 711.398 1989 949.753 1990 1320.12 1991 1411.795 1992 1595.145 1993 1738.158 1994 1727.157 1995 1727.157 1996 1851.835 1997 1829.833 1998 1811.498 1999 1815.165 2000 1778.495 2001 2005.849 2002 2038.852 2003 2035.185 2004 2024.184 2005 1928.842 2006 2020.517 2007 2086.523 2008 1892.172 2009 2493.56 2010 3358.972 2011 2654.908 2012 2306.543 2013 2189.199 2014 1818.832 2015 1657.484 2016 1873.837