For 2001, the certified farmland assessed values for soils of all productivity index values decreased 10% from the 2000 certified assessed values. This is largely the result of the interaction of the 1986 law limiting changes in certified farmland assessed valuation to no more than a 10% increase or a 10% decrease. The underlying economic conditions in Illinois agriculture are the driver of the limit down movement. Increasing production costs, relatively lower commodity prices, and a slightly increased interest rate all had a role in the decreasing certified assessed farmland values. The state of the agricultural economy in Illinois drives the use-value farmland assessment calculations. An noted above, commodity prices, general farm expenses, and interest rates all have an impact in the calculation of the assessed valuation of farmland in its use as farmland. The decrease in certified values for all soil productivity indexes was restricted by the 1986 ten percent limit law since the decrease in calculated assessment valuation from 2000 to 2001 exceeded ten percent. Each soil type identified in Illinois is assign a soil productivity index based on the production capacity of the soil. These certified assessed valuations were issued to county assessing officials in May of 2000 for use in 2001 farmland assessments. Property tax on the 2001 farmland assessments are paid in 2002.