As a result of population changes between the 1980 and 1990 censuses, 8 states gained members and 13 states had fewer members in the House of Representatives. Paralleling the pattern evident between the 1970 and 1980 censuses, the states that gained representation after the 1990 census were in the South and West, while those that declined were in the Northeast and Midwest.
Based on the 1990 Census apportionment, each member of the U.S. House of Representatives represented an average population of 572,466.
Apportionment Tables (Source of items 1 and 2: 1990 Census of Population and Housing, "Population and Housing Unit Counts," CPH-2-1.)