The return coefficient of a Member State is defined as the ratio between that Member State's percentage share of the value of all Supply contracts and that Member State's percentage contribution to the CERN Budget over the same period.

A Member State is defined as very poorly balanced if its return coefficient for Supply contracts falls below 0.40, poorly balanced if its return coefficient for Supply contracts falls below 1.00 and well balanced if it is equal or greater than that value.

The country of origin is the country where the supplies (including their components and sub-assemblies) are manufactured or undergo the last major transformation by the contractor or his sub-contractor(s).