Upgrading Tire Cost Report

Ability to calculate the average cost of a Tire, not just the calculated cost per mile. Also, the average cost of a group of the same Tire 'type' mounted to a unit.

Increase the decimal place calculation from 2 to 4.

Request to calculate the miles given with recorded tread depths. Tread depths are recorded when mounting and dismounting, it would be useful to utilize this information. Where does this info get kept on the Tire part info itself?