Year	million ton-km
1992	0.200000003
1993	0.3000000119
1994	0.400000006
1995	0.400000006
1996	0.6999999881
1997	1
1998	1
1999	1.3999999762
2000	1.434
2001	1.454
2002	1.247
2003	1.455
2004	1.335
2005	1.302
2006	1.083
2007	1.04
2008	0.974
2009	0.576
2010	4.148
2011	4.871
2012	2.252
2013	0.108996
2014	0.900996
2015	0.870362136
2016	0.003
2018	0
2019	0