The boss wants an inventory count of cars on any given pass date. The
existing table has a DELIVERED date field, for when the car is entered in
inventory; and a RELEASED date field, for when the car is sold and taken out
of inventory.

For example, the boss may want to know how many cars were in inventory on
May 2nd 2007, or June 3rd 2008, or July 25th 2008, and so on.

Thanks for your help.