(a) In counties with a board of review appointed under Section 6-5, the clerk of the board of review shall collect and analyze property transfers and property appraisals, and pursue other activities the board considers proper and necessary to aid the board in the determination of the percentage relationship, for each assessment district, between the valuations at which locally assessed property is listed and 33 1/3% of the estimated fair cash value of such property, or the values determined in accordance with Sections 10-110 through 10-140, or the percentages provided by a county ordinance adopted under Section 4 of Article IX of the Constitution of Illinois.
     (b) In counties with 3,000,000 or more inhabitants, the county assessor shall annually make available to the board of appeals (until the first Monday in December 1998 and the board of review beginning on the first Monday in December 1998 and thereafter) information utilized in the assessment of property, including, but not limited to, reports generated from the multiple regression equation and sales/ratio studies, if any. The county assessor shall make available to the board of appeals (until the first Monday in December 1998 and the board of review beginning on the first Monday in December 1998 and thereafter), upon request by any member of the board, data used in compilation of the reports and studies. The Department shall make available to the board of appeals (until the first Monday in December 1998 and the board of review beginning on the first Monday in December 1998 and thereafter) sales/ratio studies conducted by the Department.