A county assessor shall, at least on an annual basis, update property record cards, assessment rolls and any other appropriate records to reflect all changes in the fair market value, the use value, the normal assessment and the preferential assessment of all tracts of enrolled land. This subsection does not require that a county assessor recalculate the preferential assessment of all enrolled land each year, but instead requires the county assessor to maintain reasonably current records reflecting any changes in preferential assessment.
7 Pa. Code § 137b.105