Definition
Population is resident registration records of birth, death and migration (come and move). Called the registration if the report births, deaths and migration has been moved to a register, but if the reporting is still listed on the form have not been included in the register books have not been told to register.
Yes, regular is the record of a birth, death, and migration is done regularly, every month, 3 months, or 6 months.
Yes, not regular is the recording of a birth, death, and migration in an irregular manner, sometimes recorded or sometimes not recorded.
Nothing if not ever done recording a birth, death, and migration.