Year	million ton-km
1970	0.8000000119
1971	1
1972	1.1000000238
1973	1.1000000238
1974	2.2000000477
1975	4
1976	6.8000001907
1977	8.1999998093
1978	9.6000003815
1979	14
1980	26.2000007629
1981	21.3999996185
1982	21.6000003815
1983	23.7999992371
1984	30.7000007629
1985	32.5999984741
1986	31.3999996185
1987	31.5
1988	33.9000015259
1989	40
1990	44.2999992371
1991	51.2000007629
1992	69.8000030518
1993	88.0999984741
1994	122.0999984741
1995	132.8000030518
1996	105.8000030518
1997	96.5999984741
1998	104.5
1999	209.1000061035
2000	208.801
2001	233.928
2002	244.115
2003	341.232
2004	416.514
2009	564.331
2010	504.494
2011	417.582988557635
2012	338.071008606076
2013	265.615452
2014	258.367992
2015	240.107004
2016	387.310813088
2017	390.39
2018	420.98375
2019	311.15413
2020	191.96251
2021	523.2992