Year metric tons 1960 2013 1961 1700 1962 1500 1963 1400 1964 1600 1965 2924 1966 3324 1967 4236 1968 5560 1969 6500 1970 5500 1971 5600 1972 2549 1973 2975 1974 4769 1975 4949 1976 4059 1977 2046 1978 4355 1979 4500 1980 12752 1981 13130 1982 14706 1983 10122 1984 11979.78 1985 15900.6 1986 17947 1987 18622 1988 21690 1989 22058 1990 24804 1991 26106 1992 28908 1993 31103 1994 33518 1995 34448 1996 36024 1997 36925 1998 37959 1999 43643 2000 50009 2001 47336 2002 44053 2003 41994 2004 40190 2005 37783 2006 35040 2007 32166 2008 47760 2009 52227.3 2010 50116 2011 30014 2012 34664 2013 35514 2014 24643 2015 25740 2016 29929.39 2017 31883.99 2018 32154.06 2019 32345 2020 31813.55 2021 31961.33 2022 32595