Section 6. Declaration of Real Property by Owner or Administrator. —

It shall be the duty of all persons, natural or juridical, owning or administering real property, including the improvements therein, within a city or municipality, or their duly authorized representative, to prepare, or cause to be prepared, and file with provincial or city assessor, a sworn statement declaring the true value of their property, whether previously declared or undeclared, taxable or exempt, which shall be the current and fair market value of the property, as determined by the declarant. Such declaration shall contain a description of the property sufficient in detail to enable the assessor or his deputy to identify the same for assessment purposes. The sworn declaration of real property herein referred to shall be filed with the assessor concerned once every three years during the period from January first to June thirtieth commencing with the calendar year 1980, unless required earlier by the Minister of Finance.