The Manheim Used Vehicle Value Index is a measure of used vehicle prices in the US which fall into one of the 20 market classes (i.e., excludes heavy trucks, motorcycles, etc). Manheim applies statistical analysis to its database of more than 5 million used vehicle transactions annually. The per-mile adjustment is based on a simple linear regression for price and miles for each market class based on data for the current month The Index is weighted based on a 24-month rolling average of past sales by market class.