Year	million ton-km
1970	81.5000020041
1971	98.19999990579998
1972	105.1000007169
1973	111.90000090730003
1974	140.40000069110002
1975	146.3000022323
1976	160.9999996948
1977	154.6000012682
1978	165.40000063949998
1979	192.10000090320003
1980	251.70000313210002
1981	294.69999982409996
1982	318.20000033819997
1983	307.5999995395
1984	304.8999965414
1985	320.400000356
1986	284.1000046061
1987	282.3999965713999
1988	271.1999977155
1989	263.3000022994
1990	259.9000044687
1991	248.20000218629997
1992	207.2999996247
1993	215.4000003859
1994	221.6999984682
1995	237.60000398739996
1996	261.39999677220004
1997	249.90000096689997
1998	266.1999996304
1999	266.69999790210005
2000	269.32800000000003
2001	194.191
2002	126.15400000000001
2003	108.28599999999999
2004	109.01
2010	85.99349159080816
2011	77.2627685253505
2012	73.39515976456165
2013	65.8331921811429
2014	70.8181919847372
2015	42.88631012298972
2016	39.60398068606253
2017	41.32919758252649
2018	39.663228670776164
2019	32.29504920340146
2021	28.163338740999997