Different individuals, included in the Social Security file, merged with the Statistical Population Register and found in it.

Two different situations may arise:

• Affiliates included in the census (residents): People who were registered in a municipality of the Basque Country during the quarter of reference.
• Affiliates removed from the census (non-residents): People who were removed from the register of a municipality of the Basque Country or who were not yet entered during the quarter of reference.