Year	million ton-km
1975	0.6999999881
1976	0.8000000119
1977	0.8999999762
1978	0.8999999762
1979	0.8999999762
1980	0.8999999762
1981	0.8999999762
1982	1.1000000238
1983	1.2999999523
1984	1.2999999523
1985	1.2999999523
1986	1.5
1987	2.5
1988	2
1989	2
1990	2.2000000477
1992	0.1000000015
1993	0.1000000015
1994	0.200000003
1995	0.200000003
1996	0.3000000119
1998	0.400000006
2000	9
2001	6
2002	6.06
2003	6.666
2004	7.533
2005	8.06
2006	9.591
2007	8.632
2008	8.34
2009	7.581
2010	0
2011	0
2012	0