Year	million ton-km
1970	137.50000058100002
1971	151.69999833399999
1972	156.4999995158
1973	185.4000012799
1974	244.80000336450001
1975	259.9000006618
1976	311.20000007770005
1977	319.3999988586
1978	354.5000021981001
1979	453.90000051300007
1980	467.5000034049001
1981	503.8000025303
1982	527.2000000401
1983	527.2999972031
1984	508.79999577259997
1985	523.4999993143
1986	489.0000040457001
1987	539.9999976458
1988	541.7999980374999
1989	576.3000046835001
1990	533.6000063046
1991	402.90000408160006
1992	378.69999725380006
1993	367.49999985110003
1994	428.7999965846
1995	401.5999995171
1996	404.49999840540005
1997	372.0000042095001
1998	369.6000005305
1999	399.59999784850004
2000	412.38500000000005
2001	337.85600009536734
2010	573.8515870474982
2011	493.7527367267745
2012	564.0147851091097
2013	635.0061921703292
2014	561.0417835010601
2015	475.14971206194485
2016	472.69668528861314
2017	527.2982462217658
2018	556.9522502877858
2019	544.967396425727
2020	262.65182067416384
2021	482.446571564