(a) The commissioner shall by regulation establish the digest evaluation cycles for each of the counties in this state giving weight to the number of taxable parcels in each county, the geographical location of each county, and each such county's compliance with the provisions of Code Section 48-5-343. The starting date of each county's digest evaluation cycle shall be staggered so that the digest review year of one-third of the counties shall occur each year.
(b) For those digests submitted by counties in their designated digest review year, the commissioner shall begin his or her review of the digest in accordance with Code Section 48-5-343 and shall, within 30 days after the date the state auditor furnishes to the commissioner the ratios established pursuant to paragraph (8) of subsection (b) of Code Section 48-5-274 or by August 1 of the next succeeding tax year, whichever comes later, approve or conditionally approve the digest.