Year	million ton-km
1970	300.4000076427001
1971	390.00000426919996
1972	463.8000042215001
1973	626.5000113025002
1974	703.1999927537
1975	807.3999931366001
1976	1016.6000064907997
1977	1116.4000167846998
1978	1195.5000009315
1979	1403.1000168100002
1980	1431.5999739911995
1981	1529.4000137596
1982	1684.4000020624
1983	2029.0999744534004
1984	2232.599972635299
1985	2059.1999868452995
1986	1978.4000042078003
1987	2313.0000341535
1988	2595.9000454545994
1989	2794.5000072496005
1990	2664.099986650101
1991	2484.5999876034994
1992	2837.8000061512
1993	3103.4999673961997
1994	3630.3999755977998
1995	4049.2001246513005
1996	4089.2000005843
1997	4382.9001052975
1998	4455.700064480399
1999	4789.3000190852
2000	4994.165
2001	4960.746
2002	5951.593
2003	6876.218000000001
2004	8257.369999999999
2005	8894.202
2006	9974.92
2007	11267.296
2008	14140.434000000001
2009	15602.688999999998
2010	16736.950171039447
2011	18088.195280607295
2012	20569.353514595598
2013	23109.88845635068
2014	25436.740580201604
2015	26768.909282391076
2016	28790.08894041587
2017	31578.23967157729
2018	33037.804400621695
2019	32670.094957926725
2020	28287.816101074
2021	34622.1897700168