Year metric tons 1960 17100 1961 18000 1962 19500 1963 19900 1964 20100 1965 20000 1966 20500 1967 20500 1968 22000 1969 22300 1970 22200 1971 22200 1972 22200 1973 22600 1974 22600 1975 22600 1976 24700 1977 23570 1978 26610 1979 28520 1980 26060 1981 28530 1982 29710 1983 29500 1984 29780 1985 26290 1986 23942 1987 27200 1988 29200 1989 30200 1990 31500 1991 33113 1992 35023 1993 40014 1994 44013 1995 44003 1996 45009.6 1997 47010 1998 49513 1999 49513.5 2000 53010 2001 58007.5 2002 57007.5 2003 59007.5 2004 63007.5 2005 59007.5 2006 57007.5 2007 65516.5 2008 68602.5 2009 71698 2010 71358 2011 71008 2012 34008 2013 33708 2014 33508 2015 33008 2016 35502 2017 38390 2018 41041 2019 40770 2020 37660 2021 40970 2022 44250