Indices used for labour, materials and transport elements
The calculation of the amount of Variation of Prices will be based on indices published in the Office for National Statistics Monthly Digest of Statistics ("the Digest"):
■ The labour element index is calculated from Table 18.11 of the Digest, the Average Earnings Index: All employees: by industry (unadjusted), using the index for Electrical and Optical equipment, with the base date 1990 = 100.
■ The materials element index is calculated from Table 18.6 of the Digest, the Index of Producer Prices, using the SIC 1992 index for Electrical and Optical equipment.
■ The transport element is calculated from Table 18.2 of the Digest, using the Motoring Expenditure Index of Retail Prices, with the base date January 1987 = 100.
■ The telecommunications element index is calculated from telecommunications service price indices, comprising sets of public telecommunications operator services which meet criteria defined in the agreement.