Year	million ton-km
1970	2.5
1971	3.2999999523
1972	4.8000001907
1973	5.8000001907
1974	9.6999998093
1975	10.8999996185
1976	11
1977	11.6000003815
1978	13.1999998093
1979	10.6999998093
1980	9.3999996185
1981	9.8999996185
1982	9.6999998093
1983	16.6000003815
1984	19.6000003815
1985	19.1000003815
1986	18.8999996185
1987	24.2000007629
1988	20.6000003815
1989	16.2999992371
1990	18.7999992371
1991	19.7000007629
1992	18.3999996185
1993	19.7999992371
1994	19.7999992371
1995	21.7999992371
1996	24.8999996185
1997	20.8999996185
1998	23.7999992371
1999	29.5
2000	29.196
2001	26.391
2002	56.588
2003	48.859
2004	37.698
2005	15.823
2006	15.348
2007	15.655
2008	16.25
2009	10.272
2010	0
2011	0
2012	0
2013	0
2015	1.396
2016	4.506984
2017	2.83938
2018	4.58628
2019	0