Year metric tons 1960 4628165 1961 6504496 1962 8499409 1963 8585537 1964 11314630 1965 9320757 1966 11434801 1967 12570593 1968 13366648 1969 11701275 1970 15328783 1971 13759326 1972 7383558 1973 5198183 1974 7351087 1975 6561252 1976 8092233 1977 6646830 1978 8782309 1979 9973268 1980 9441392 1981 10258802 1982 11323098 1983 9156810.899999999 1984 11975745.9 1985 13709189.52 1986 15799970.28 1987 13821897.98 1988 16229762.719999999 1989 17719291.900000002 1990 15977252.91 1991 16958099.89 1992 17821951.55 1993 19178340.08 1994 24145837.27 1995 21497006.38 1996 21679980.46 1997 19159642.36 1998 12382957.23 1999 18237572.53 2000 19909256.4 2001 17076260.5 2002 18222823.88 2003 14794939.05 2004 19727519.43 2005 18963471.56 2006 16639075.3 2007 16483444.69 2008 16697988.66 2009 15972500.83 2010 12226355 2011 16594578.820000002 2012 12554264.18 2013 12910261.739999998 2014 11071917.530000001 2015 11689592.790000001 2016 10458810.670000002 2017 11494113.080000002 2018 14514721.76 2019 12116185.579999998 2020 12729907.72 2021 14294607.84 2022 12943545.690000003