Year	million ton-km
1973	0.6999999881
1974	0.8999999762
1975	1
1976	1
1977	1.2000000477
1978	2.0999999046
1979	2.7999999523
1980	2.7999999523
1981	3.0999999046
1982	3.4000000954
1983	3.4000000954
1984	3.7000000477
1985	3.7999999523
1986	6
1987	10.3000001907
1988	15
1989	20.3999996185
1990	5.0999999046
1991	23.2999992371
1992	33.7999992371
1993	37.7000007629
1994	55.9000015259
1995	82.5999984741
1996	75.4000015259
1997	17.5
1998	17.5
1999	83.5999984741
2000	90.819
2001	84.478
2002	67.15
2003	68
2004	74.769
2005	92.108
2006	95.792
2007	101.54
2008	96.057
2009	65.564
2010	77.084703141
2011	84.6407332797888
2012	90.9405521462482
2013	69.333
2014	78.513996
2015	83.6865043020511
2016	86.955
2017	102.59573
2018	106.8282
2019	108.9135
2020	21.804
2021	6.39867