Year	million ton-km
1970	5.9000000954
1971	7.3000001907
1972	8.1000003815
1973	8.3999996185
1974	10.8999996185
1975	11.6000003815
1976	13.6999998093
1977	7.8000001907
1978	0.6999999881
1979	0.8000000119
1980	26.5
1981	26.7000007629
1982	27.2999992371
1983	30.8999996185
1984	31.7999992371
1985	36
1986	37.4000015259
1987	29.1000003815
1988	27.2000007629
1989	29.3999996185
1990	26.1000003815
1991	26.8999996185
1992	28.1000003815
1993	30.6000003815
1994	32.2000007629
1995	32.2000007629
1996	34.5999984741
1997	38.0999984741
1998	34.7000007629
1999	53.5
2000	58.174
2001	48.832
2002	49.31
2003	54.251
2004	61.267
2005	65.542
2006	77.975
2007	70.17399999999999
2008	67.986
2009	61.742
2010	0
2011	0
2012	0
2013	0