Year metric tons 1960 200744 1961 210986 1962 221087 1963 232702 1964 245339 1965 259445 1966 270514 1967 284007 1968 329697 1969 346887 1970 367117 1971 394265 1972 418392 1973 448093 1974 501110 1975 523098 1976 568461 1977 622171 1978 726817 1979 811065 1980 934314 1981 1011344 1982 1129945 1983 1263041 1984 1359779 1985 1476152 1986 1532860 1987 1768640 1988 1950299 1989 2142148 1990 2206092 1991 2488830 1992 2831844 1993 2948564 1994 3314002 1995 3656280 1996 3839662 1997 4060596 1998 4292610 1999 4761156 2000 4939954 2001 5519165 2002 6066390.76 2003 6755100.1 2004 8033360.4 2005 8800452.77 2006 9674388.6 2007 10336453.6 2008 11924463.350000001 2009 12253082.11 2010 13125752.61 2011 13627567.23 2012 14792553.540000001 2013 15368355.76 2014 16142446.82 2015 17014920.07 2016 17713201.450000003 2017 18787403.47 2018 20722819.299999997 2019 21826008.71 2020 23059856.34 2021 23943455.55 2022 24854207.819999997