The index declined to 200.0 and is now down 10.6% from a year ago. In October, daily MMR Retention, which is the average difference in price relative to current MMR, averaged 98.2%, meaning market prices were below MMR values. Used Retail Sales Estimates Declines in OctoberLeveraging a same-store set of dealerships selected to represent the country from Dealertrack, Manheim initially estimates that used retail sales declined 9% in October from September and that used retail sales were down 13% year over year. Credit transactions heavily influence the same-store data series, and growth in cash purchase activity is likely causing the estimates to decline more than actual market sales. Most of the index decline was driven by a 7.5% decline in views of the present situation.