Year	million ton-km
1970	9.3000001907
1971	4.6999998093
1972	4.5
1973	9.6000003815
1974	9.8000001907
1975	6.4000000954
1976	6.9000000954
1977	9.5
1978	12.8999996185
1979	30.8999996185
1980	39.7999992371
1981	38.7999992371
1982	36.5999984741
1983	33
1984	42.5
1985	50.7000007629
1986	58.5999984741
1987	70
1988	73.5999984741
1989	68.4000015259
1990	63.2000007629
1991	68
1992	54.0999984741
1993	85.4000015259
1994	38
1995	32.2000007629
1996	32.9000015259
1997	53.7999992371
1998	82.1999969482
1999	33
2000	15.456
2001	6.354
2002	7.989
2003	4.291
2004	4.99
2005	5.439
2006	5.874
2007	5.614999999999999
2008	4.662
2009	3.229
2010	129.7315
2011	126.4039
2012	121.402590579105
2013	112.059962
2014	82.101
2015	64.037777
2016	60.17416
2017	57.68029
2018	64.20469
2019	50.80511
2020	10.604353816
2021	4.29491