Year	metric tons
1960	498365
1961	499123
1962	529681
1963	591478
1964	646376
1965	715572
1966	760840
1967	804352
1968	985764
1969	964447
1970	1103203
1971	1123675
1972	1228537
1973	1314391
1974	1400319
1975	1470726
1976	1378731
1977	1505870
1978	1590167
1979	1607135
1980	1715211
1981	1777203
1982	1903187
1983	2135793.4
1984	2080607
1985	2064326.7
1986	2097164.5
1987	2228233.4
1988	2279701.4
1989	2393133.4
1990	2522319
1991	2618883
1992	2659598
1993	2656487
1994	2742710
1995	2829131
1996	2825515
1997	2820119
1998	2867336
1999	2943418
2000	3020919
2001	3182008
2002	3383487
2003	3632712
2004	3952056
2005	4189329
2006	4433654.49
2007	4735293
2008	4958398.1
2009	4991228.4399999995
2010	5048839
2011	4828900
2012	4748535.32
2013	4575228.58
2014	4586796.27
2015	4502146
2016	4227937.75
2017	4126941.23
2018	4126424.45
2019	4189087.04
2020	4237749.79
2021	4088382.66
2022	4120499.26