Compensated gross tonnage
Compensated Gross Tonnage (CGT) is an indicator of the amount of work necessary to build a given ship and is calculated by multiplying the tonnage of a ship by a coefficient, which is determined according to the type and size of a particular ship. The standard CGT system was developed in 1977 by the OECD so that inter-country shipbuilding output could be reasonably compared, as different types of ships require a greater or lesser degree of work relative to their gross tonnage.
Source: Wikipedia — Compensated gross tonnage (CC BY-SA 4.0)