Year	million ton-km
1975	1.6000000238
1976	1.8999999762
1977	1.8999999762
1978	2.0999999046
1979	3
1980	3
1981	3.5
1982	0.200000003
1983	0.3000000119
1984	0.200000003
1985	0.200000003
1986	0.3000000119
1987	0.3000000119
1988	0.3000000119
1989	0.3000000119
1990	0.3000000119
1991	0.3000000119
1992	0.3000000119
1993	0.400000006
1994	0.400000006
1995	0.400000006
1996	0.400000006
1997	0.5
1998	1.1000000238
1999	1.5
2000	1.598
2001	1.764
2002	1.637
2003	1.644
2004	0.59
2005	0.571
2006	0.561
2007	0.5680000000000001
2008	0.5860000000000001
2009	0.489
2010	0.073942936
2011	0.0921231146396359
2012	0.120103571080943
2013	0.145272
2014	0.176256
2015	0.17273088
2016	0.17480365
2017	0.173580024
2018	0
2019	0