The South-East Lancashire conurbation consists of Manchester and the surrounding towns. The full definition will be found in the Abstract of Regional Statistics 1973.

The income figures used in calculating these averages are derived from the surveys of personal incomes for the years shown. They exclude non-taxable receipts, such as certain national insurance benefits as well as income below the exemption limit for tax. That limit has varied as follows: 1949–50, £135; 1959–60, £180 ; 1964–65 to 1968–69, £275 ; 1969–70, £330; 1970–71 and 1971–72, £420.

Up to and including 1964–65 the income of taxpayers was allocated to the regions in which their tax was assessed, except for the income of civil servants, the Forces and the Merchant Navy, which was included in the figure for England but not otherwise allocated to regions. Since 1965–66 the income of civil servants has as far as possible been allocated to the regions in which they reside and since 1969–70 the income of most other taxpayers has also been allocated on the basis of place of residence. The income of self-employed persons, however, continues to be allocated on a place of assessment basis and there has been no change in the treatment of the Forces, the Merchant Navy and those civil servants whose incomes cannot be allocated according to their place of residence.

The population figures used relate to mid-1949, mid-1959, etc., and include all individuals of all ages whether they have an income or not.

The estimates for 1971–72 are provisional.