Year	million ton-km
1970	1.3999999762
1971	1.6000000238
1972	2.7999999523
1973	3.7999999523
1974	5.0999999046
1975	5.6999998093
1976	6.6999998093
1977	8.1999998093
1978	10.1000003815
1979	11
1980	11.6000003815
1981	13.3999996185
1982	16.3999996185
1983	19.5
1984	18.2999992371
1985	15.8999996185
1986	14.6000003815
1987	18.7000007629
1988	16.7999992371
1989	18.7999992371
1990	19.1000003815
1991	17.7999992371
1992	16.2000007629
1993	16.3999996185
1994	17.2999992371
1995	18.6000003815
1996	18.3999996185
1997	18.7000007629
1998	20.2999992371
1999	19.2000007629
2000	20.818
2001	20.106
2002	19.189
2003	19.236
2004	20.291
2005	18.048
2006	18.572
2007	15.344
2008	15.381
2009	13.927
2010	14.640172
2011	12.7290692703312
2012	15.5990812234352
2013	14.683452
2014	13.28618
2015	10.35424112
2016	8.096
2017	12.124027
2018	13.234265
2019	13.092473
2020	6.546656
2021	5.602932