Oversees the County-wide revaluation project; maintains records of assigned property values, updating as necessitated by changes in land use; develops and sets valuation policy to be used in the revaluation program; analyzes and researches the real estate market, develops valuation models for all classes of property, researches and defines neighborhoods, and reviews and approves final schedule of values and supervises its application. Numerical Aptitude: Requires the ability to utilize mathematical formulas; to add and subtract; to multiply and divide; to calculate decimals and percentages; to interpret graphs; to compute discount, interest profit and loss, ratio and proportion, etc. to perform calculations involving variables, formulas, to perform statistical calculations which include frequency distributions, reliability and validity of tests, correlation techniques, factor analysis.