Year	million ton-km
1970	1.7999999523
1971	1.8999999762
1972	3.5
1973	2.9000000954
1974	2.5999999046
1975	2
1976	2.4000000954
1977	2.2000000477
1978	0.5
1979	1.7999999523
1980	9.6999998093
1981	26.7999992371
1982	39.7999992371
1983	44.5999984741
1984	59.5999984741
1985	67.5999984741
1986	54.7000007629
1987	49.0999984741
1988	61.7000007629
1989	75.4000015259
1990	93.4000015259
1991	100.6999969482
1992	109.8000030518
1993	104.4000015259
1994	109.9000015259
1995	156
1996	158.6000061035
1997	173.8999938965
1998	156.5
1999	179.1999969482
2000	255.708
2001	217.567
2002	203.126
2003	238.009
2004	312.627
2005	310.362
2006	325.413
2007	343.641
2008	331.457
2009	278.998
2010	339.048919353
2011	364.50263
2012	405.42043
2013	385.12
2014	384.70865414
2015	381.6320526
2016	403.075583974751
2017	398.473464249
2018	436.198
2019	394.05
2020	226.479
2021	412.484