Year	metric tons
1960	0
1961	0
1962	0
1963	0
1964	0
1965	0
1966	0
1967	0
1968	0
1969	0
1970	0
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	15
1989	12
1990	31
1991	35
1992	35
1993	30
1994	30
1995	30
1996	30
1997	30
1998	30
1999	30
2000	30
2001	30
2002	30
2003	30
2004	40
2005	40
2006	40
2007	40
2008	46
2009	46
2010	46
2011	75
2012	78.34
2013	69.8
2014	139
2015	149
2016	185
2017	222
2018	223.62
2019	209.27
2020	181
2021	193
2022	190.88