Source: UNCTAD Review of Maritime Transport, various years.
Ton-Miles Shipped by Maritime Transportation, 1970-2012 (in billions)
In 2012 the total ton-miles performed by maritime transportation reached a record just over 44,000 billions, with raw materials the dominating. For instance, oil, iron ore, coal and grain account for 28% of the ton-miles while other dry cargoes, which mostly include containers, accounted for 40%. Oil alone accounted for 25% of ton-miles in 2012, but this share is significantly lower than in 1970 when it accounted for 60% of the global ton-miles. Global maritime trade, weight wise, thus remains dominated by basic commodities.
Over the 1970-2008 period the average distance over which cargoes were transported did not change; about 4,100 nautical miles. The average transport distance only marginally increased for oil (from 4,500 to 4,600 nautical miles) and slightly decreased for other dry cargoes (from 3,100 to 2,900 nautical miles). Only for major bulk trades, such as coal and iron ore, is there a significant lengthening of the voyage distance (from 4,600 to 5,400 nautical miles), mainly because of new major consumers of this imported cargo, notably China.