Year	million ton-km
1970	3.0999999046
1971	3.0999999046
1972	2.4000000954
1973	2.5
1974	3.0999999046
1975	2.9000000954
1976	2.7999999523
1977	2.7000000477
1978	2.5
1979	2.7999999523
1980	3.5999999046
1981	6.5
1982	4.5999999046
1983	6.5999999046
1984	7.5
1985	9.3999996185
1986	10.1000003815
1987	12.1000003815
1988	13.3999996185
1989	13.6000003815
1990	15.6999998093
1991	19.1000003815
1992	20.1000003815
1993	22.5
1994	23.7999992371
1995	24.1000003815
1996	29.5
1997	32.7999992371
1998	29.8999996185
1999	31.3999996185
2000	39.949
2001	32.97
2002	18.901
2003	16.63
2004	6.652
2010	5.22980484930983
2011	3.56603511599799
2012	2.41801639475519
2013	1.31802
2014	1.332792
2015	0.844630332
2016	0.846429394
2017	0.262714068
2018	0
2019	0