Year	million ton-km
1970	56.7999992371
1971	63.9000015259
1972	75.8000030518
1973	112.6999969482
1974	143.6000061035
1975	142.3000030518
1976	146.3000030518
1977	173.8000030518
1978	222.1000061035
1979	237
1980	251.1999969482
1981	311.3999938965
1982	318.200012207
1983	367.299987793
1984	442.8999938965
1985	391.799987793
1986	308.200012207
1987	268.1000061035
1988	238.3000030518
1989	205.6000061035
1990	179.1999969482
1991	191
1992	263.200012207
1993	332.8999938965
1994	276.5
1995	263.1000061035
1996	328.5
1997	420.3999938965
1998	535.5999755859
1999	688.4000244141
2000	687.569
2001	755.516
2002	783.844
2003	891.465
2004	928.987
2005	923.383
2006	1232.995
2007	939.1990000000001
2008	760.889
2009	676.413
2010	1025.562
2011	1072.91477981187
2012	1174.66680577935
2013	1122.986468
2014	1042.73626391249
2015	892.734324084
2016	767.271186
2017	833.347947527025
2018	696.730006
2019	565.20947
2020	102.392463
2021	15.131581