I have no suggestions on where to find what you are looking for.... but I do suggest that you clarify what question you are really asking.
Are you looking for the number of commercials actually broadcast? When you use the term "produced" that has the sound of asking how many different scripts were turned into audio and video with no regard to how many times each was put on the air... and would you count commercials "roduced" but never aired because the agency or sponsor turned them down and order new "production" more to their liking?
I could "produce" one commercial for a radio station and they could broadcast that one recording ten times a day for 365 days. Is that ONE produced, or is that 3,650 commercials "produced"?