Specifically, any change in the judicial districts' boundaries would have to be determined by use of population data from the United States Bureau of the Census identical to those from the actual enumeration conducted by the Census Bureau for the apportionment of the Representatives of the U.S. House of Representatives in the U.S. decennial census. The apportionment data for redistricting, however, could not include any population that was not allocated to specific census blocks within the State, such as Americans residing overseas, even if that population were legally included in the apportionment data for this State for the purpose of allocating seats among the states. District boundaries could not be determined by use of Census Bureau population counts derived from any other means, including the use of statistical sampling to add or subtract population by inference. Other governmental census figures of total population could be used if taken after the last decennial U.S. census and the U.S. census figures were not adequate for the purposes of the Act. A contract could be entered into with the U.S. Census Bureau or any other governmental unit to make any special census if the latest U.S. decennial census figures were not adequate for the Act's purposes.