Year	metric tons
1960	400
1961	400
1962	400
1963	400
1964	400
1965	500
1966	500
1967	500
1968	500
1969	500
1970	400
1971	500
1972	500
1973	600
1974	726
1975	901
1976	1019
1977	1197
1978	1210
1979	2000
1980	1994
1981	2093
1982	2134
1983	2237
1984	2385
1985	2561
1986	2814
1987	2790
1988	2731
1989	2699
1990	1644
1991	1935
1992	2237
1993	2375
1994	2499
1995	2727
1996	2955
1997	2924
1998	4166
1999	4694
2000	4231
2001	4947
2002	5260
2003	4754
2004	3352
2005	2566
2006	2882
2007	2727
2008	2293
2009	1955
2010	2076
2011	2130.34
2012	2323.16
2013	1896
2014	1921.03
2015	1803.03
2016	1605
2017	1401
2018	1244.39
2019	1212.61
2020	1097.12
2021	1115.21
2022	1326.03