Section 35 ILCS 200/16-8 - Books and records of chief county assessment officer(a) In counties with 3,000,000 or more inhabitants, the chief county assessment officer shall maintain records of the assessed value of each parcel of property and shall enter upon the property record card of each town or city lot or parcel of land the elements (or basis) of valuation and computations that are taken into consideration by the chief county assessment officer in ascertaining and determining the fair cash value of each town or city lot or parcel of land and of each improvement thereon, including the elements (shown by percentages or otherwise) that were taken into consideration as enhancing or detracting elements (such as depth, corner, alley, railway or other elements). The assessment officer shall maintain the records for at least 10 years. Upon request by the board of appeals (until the first Monday in December 1998 and the board of review beginning the first Monday in December 1998 and thereafter), the officer shall immediately furnish all of the requested records to the board. The records shall be available, on request, to the taxpayer. The chief county assessment officer shall certify, in writing, the amount of the assessment to the board. If the records maintained by the chief county assessment officer at the time the assessment is certified to the board under subsection (a) contain none of the elements (or basis) of valuation for the parcel, then any increase by the chief county assessment officer shall be considered invalid by the board acting on a complaint under Section 16-120; and no action by the board under Section 16-120 shall result in an increase in the valuation for the parcel for the current assessment year.(b) In counties with 3,000,000 or more inhabitants, the notice given by the chief county assessment officer to a taxpayer of a proposed increase in assessment shall designate the reason for the increase. If a taxpayer files an assessment complaint with the chief county assessment officer, the notification to the taxpayer of a determination on the assessment complaint shall designate the reason for the result.(c) The provisions of this Section shall be applicable beginning with the assessment for the 1997 tax year.P.A. 89-718, eff. 3/7/1997; 90-4, eff. 3/7/1997.