Year metric tons 1961 9285 1962 9053 1963 9173 1964 9397 1965 9417 1966 8850 1967 8862 1968 8796 1969 8458 1970 8595 1971 8635 1972 6800 1973 7900 1974 8368 1975 7750 1976 8400 1977 9070 1978 9890 1979 10570 1980 10830 1981 10487 1982 11400 1983 12800 1984 13662 1985 13500 1986 21060 1987 23858 1988 25421 1989 20695 1990 23664 1991 24677 1992 25369.94 1993 27320 1994 30506 1995 29451.62 1996 29311.16 1997 24896.67 1998 27128.84 1999 27760.83 2000 26900 2001 26168.46 2002 25046.04 2003 32075.3 2004 31334.8 2005 35308.98 2006 33170.89 2007 34100 2008 36286.75 2009 39782.49 2010 40754 2011 42405.02 2012 43407.52 2013 44201.82 2014 44781.36 2015 45415.03 2016 45999.72 2017 46425.6 2018 47181.39 2019 46535.57 2020 46714.19 2021 46810.38 2022 46686.71