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	0
1989	3
1990	2
1991	2
1992	2
1993	2
1994	3
1995	3
1996	2
1997	2
1998	1
1999	1
2000	2
2001	2
2002	4
2003	4
2004	5
2005	5
2006	5
2007	18
2008	20
2009	41.88
2010	25.11
2011	23.58
2012	35.91
2013	19.9
2014	29.33
2015	26.19
2016	23.8
2017	20.7
2018	22.7
2019	17
2020	15
2021	11.2
2022	10