Fuels are here defined to comprise all products in section 3 of the SITC. These products are: coal, coke and briquettes, petroleum, petroleum products and related materials, gas and electric current.

The unit value indices are obtained from national sources, except those of a few countries which the United Nations Statistics Division compiles using their quantity and value figures.

For countries that do not compile indices for fuel imports conforming to the above definition, sub-indices are aggregated to approximate an index of SITC section 3.

Unit value indices obtained from national indices are rebased, where necessary, so that 2000=100. Indices in national currency are converted into U.S. dollars using conversion factors obtained by dividing the weighted average exchange rate of a given currency in the current period by the weighted average exchange rate in the base period. All aggregate unit value indices are current period weighted. The volume indices are derived from the value data and the unit value indices. All aggregate volume indices are base period weighted.

The figures in table 19 are calculated from those prepared for tables 18 and 38.