The duty of the county assessor is to appraise and assess all real property between the first Monday of January and the first of July, and all personal property between the first Monday in January and the thirty-first of May. All property in the state shall be assessed according to its value on the first of January except merchants and manufacturers inventory that is assessed at its average value during the year immediately preceding the first of January. The assessor must make an abstract of assessment showing the total assessed value of the county. On August 1st, the assessor turns over to the County Equalization Board his/her Real Property Assessment Book and his/her Personal Property Assessment Book. After August 1st, the County Equalization Board and not the assessor, has the legal authority to make value changes in any of the assessment books. The assessor is required to maintain current appraisal and assessment records by securing necessary filed data and making changes in valuations as they occur in land use and improvements. He/she is also charged with staying abreast of all property transactions within the county and keeping a file on all properties updated throughout the year.