I am working on a presentation regarding gas stations in the United
States. I dont need "exact" answers, but i do require a "source" for
any statistics quoted. I am going to list each of my questions as a
separate entry:

Q4)I am trying to find out the trend for Gasoline Sold by "Channel"
(in both dollars and gallons) for gasoline in the United States over
the past five years
(ten if possible)

Ideally, i am looking for how much gasoline is sold by supermarkets,
convenience stores, Mass Merchandisers such as Walmart, Costco, Kmart,
Target, etc

And of course how much of hte gasoline is sold by traditional gas
stations (chains and independents). I am hoping to prove that over the
past 5 -10 years that non-traditional sales of gasoline have increased
to over 10% of the market and that has had the effect of decreasing
prices where supermarket/Walmart competition is most competitive.

Bonus dollars will be paid for additional relevant information on
"gross margin" (example - by geography, by independent dealers versus
national chain, etc)