Year	metric tons
1960	4850516
1961	5316768
1962	5653517
1963	5857487
1964	6112428
1965	6425662
1966	6757463
1967	7038291
1968	7589424
1969	7757265
1970	7796849
1971	8368112
1972	9061305
1973	9371148
1974	9492445
1975	9679352
1976	10048650
1977	10813651
1978	11055351
1979	10605778
1980	10563686
1981	11175126
1982	11853829
1983	12367320.99
1984	12519780.14
1985	13006932.1
1986	14227785.59
1987	15490689.69
1988	15637767.65
1989	16437078.58
1990	16958050.33
1991	17993598.94
1992	19511443.68
1993	20908572.5
1994	22889051.1
1995	24929468.16
1996	26483082.35
1997	27230766.92
1998	28236714.75
1999	28574474.47
2000	28767907.830000002
2001	28690748.250000004
2002	29104467.970000003
2003	29913546.580000002
2004	30680084.33
2005	30915182.53
2006	31361653.85
2007	31601030.349999998
2008	31195715.41
2009	31334021.02
2010	31716912.650000002
2011	32195422.209999997
2012	32717775.009999998
2013	33356069.78
2014	34623893.96
2015	35014208.22
2016	34621702.72
2017	34680326.45
2018	34251645.26
2019	33599052.78000001
2020	32505788.770000007
2021	31798725.27
2022	31803370.619999997