Year metric tons 1960 1700 1961 2550 1962 2550 1963 2550 1964 3400 1965 4050 1966 2600 1967 4000 1968 5700 1969 5450 1970 5000 1971 5700 1972 5750 1973 4450 1974 3861 1975 5005 1976 4629 1977 5924 1978 6768 1979 8803 1980 6550 1981 6295 1982 7940 1983 11331 1984 9471 1985 11185 1986 22188 1987 25974 1988 20579 1989 17463 1990 16140 1991 27377 1992 23963 1993 24820 1994 14337 1995 25741 1996 21260 1997 23780 1998 15468 1999 22569 2000 17915 2001 22292 2002 15789 2003 17343 2004 17569 2005 21139 2006 22546 2007 16636 2008 14160 2009 12408 2010 12075 2011 10214 2012 11202 2013 12809 2014 9574 2015 12841 2016 13074 2017 11652 2018 12123 2019 11947 2020 15846 2021 21680 2022 20193