Lifetime supply...

...of legal size white envelopes...just bought a new box..I like to buy in larger quantities to save money.

At the rate of one per month (my current usage) and given the advent of electronic bill pay and invoicing, the ETCSD (estimated time of complete supply depletion) will be some time around the middle of the year 2029.

Hmh...might have done this calculation while I was at Office Max.