internal_id_type[1] = 54: Type of Household (clustered)
internal_id[1] = 1: One full-time working person
internal_id[1] = 2: One pensioneer
internal_id[1] = 3: Two full-time working persons
internal_id[1] = 4: Two pensioneers
internal_id[1] = 5: One full-time and one part-time working person
internal_id[1] = 6: Two full-time working persons, one child
internal_id[1] = 7: One full-time and one part-time working person, one child
internal_id[1] = 8: Two full-time working persons, two children
internal_id[1] = 9: One full-time and one part-time working person, two children
internal_id[1] = 10: Two full-time working persons, three children
internal_id[1] = 11: One full-time and one part-time working person, three children