Year metric tons 1960 80639 1961 86172 1962 89263 1963 88224 1964 93148 1965 93898 1966 104339 1967 112101 1968 104175 1969 105690 1970 108706 1971 114121 1972 118952 1973 129830 1974 136244 1975 149633 1976 156744 1977 173780 1978 189266 1979 202202 1980 225296 1981 269959 1982 273541 1983 303941 1984 330764 1985 359626 1986 411552 1987 456727 1988 499597 1989 527897 1990 599824 1991 607507 1992 645368 1993 710414 1994 703522 1995 743092 1996 881098 1997 777547 1998 747007 1999 882989 2000 993727 2001 1076749 2002 1137151 2003 1228559 2004 1468612 2005 2124093 2006 2479247 2007 3137376 2008 3854944 2009 4712846.53 2010 6277924.49 2011 7937071.54 2012 9599764.82 2013 13301407.93 2014 14375286.83 2015 15649311.1 2016 16002319.09 2017 16118238 2018 15771806 2019 15425627.33 2020 14845014.41 2021 14493522.61 2022 14633869.09