Year metric tons 1961 5176370 1962 5239880 1963 5135570 1964 5305080 1965 5452464 1966 5583972 1967 6179853 1968 6177456 1969 7472275 1970 7595768 1971 7374862 1972 6459350 1973 7421393 1974 8146691 1975 8839298 1976 9327624 1977 10083284 1978 10313167 1979 10834585 1980 10775175 1981 11215910 1982 11670615 1983 10647242 1984 11269139 1985 12727856 1986 13337939 1987 12818171 1988 13399121 1989 13981140 1990 14987250 1991 14332247.29 1992 13750626.86 1993 14235789.18 1994 15062259.56 1995 14673161.82 1996 15439998.41 1997 15604612.06 1998 12385313.93 1999 16372330.55 2000 16901159.42 2001 17480298.91 2002 17590069.12 2003 18115689.95 2004 19910353 2005 19856348 2006 21408902.02 2007 22977304 2008 23744012 2009 23300701 2010 22149369 2011 23655648 2012 25440477.82 2013 25817440.51 2014 26739121.85 2015 25669246.05 2016 24846678.08 2017 27191819.46 2018 26838576.91 2019 26794250.87 2020 27413962.2 2021 28261089.87 2022 28012590.81