Year	metric tons
1960	12000
1961	12000
1962	15000
1963	14984
1964	14976
1965	14968
1966	17952
1967	17928
1968	17904
1969	17872
1970	19840
1971	19784
1972	19728
1973	19656
1974	19568
1975	21464
1976	21336
1977	21192
1978	21016
1979	22816
1980	22592
1981	22320
1982	22016
1983	23672
1984	23500
1985	22000
1986	21000
1987	22000
1988	21000
1989	20000
1990	18000
1991	18500
1992	19240
1993	19500
1994	23800
1995	27370
1996	23000
1997	18857
1998	19642
1999	30041
2000	29250
2001	31000
2002	33440
2003	29800
2004	29800
2005	26560
2006	26925
2007	28410
2008	29200
2009	30800
2010	30900
2011	34000
2012	34106
2013	38946
2014	60237
2015	62635
2016	57400
2017	59069
2018	60508
2019	64701
2020	70001
2021	71000