In determining population and degree of land subdivision for purposes of meeting the requirements of Code Section 36-36-54, the municipal corporation shall use methods calculated to provide reasonably accurate results. In determining, on appeal to the superior court, whether the standards set forth in Code Section 36-36-54 have been met, the reviewing court shall accept the estimates of the municipal corporation:

(1) As to population, if the estimate is based on the number of dwelling units in the area multiplied by the average family size in the area or in the county or counties of which the area is a part, as determined by the last preceding federal census or based on a new enumeration carried out under reasonable rules and regulations by the annexing municipal corporation, provided that the court shall not accept such estimates if the petitioner on appeal demonstrates that the estimates are in error in the amount of 10 percent or more;

(2) As to total area, if the estimate is based on an actual survey, on county tax maps or records, on aerial photographs, or on some other reasonably reliable map used for official purposes by a governmental agency, unless the petitioner on appeal demonstrates that the estimates are in error in the amount of 5 percent or more; and

(3) As to degree of land subdivision, if the estimates are based on an actual survey, on county tax maps or records, on aerial photographs, or on some other reasonably reliable source, unless the petitioner on appeal shows that the estimates are in error in the amount of 5 percent or more.