There are no mint records of coinage by hub type. The best we can do is estimate based on surveying auction archives. John Reynolds did this for the known thin versus thick ribbon reverse types for his BCCS article. I was doing the same before I became aware of his article. I added my own census of the Rev1/2/3. Below is a screenshot of my spreadsheet. I never finished counting up 1904-S and 1905-S so I used Reynolds' numbers. Note how odd it is that for 1902-S, the majority are from the new Rev3 thick ribbon hub, but then for 1903-S they switched back to the old Rev2 thin ribbon hub and Rev3 is scarce, I would say the scarcest of all the anomalies. The Jan-Mar and Apr-Dec numbers are totals/% based on the monthly coinage report. For 1901 I was demonstrating how my census numbers line up with what I believe was a late March implementation of the Rev3 thick ribbon hub. I can't believe I don't get paid for this stuff.
@KBBPLL . Thanks for the information. Don't mean to be such a pest but I'm weak at mathamatics. not even sure I spelled it right. james
Follow-up on the 1909 nickels. I contacted John Dannreuther, showed him this thread, and told him about what looks like the design hub doubled coin. He never saw one while looking for pictures to use for 1909 and didn't expect to see something like that but thinks it's pretty neat and wishes he had before going to print. He also likes the "Beer Belly B" term.
I have to give credit to @KBBPLL for coming up with the name "Beer Belly B". I originally referred to it as the "Pregnant B". Which I don't think was a name he was very keen on. As we conversed back and forth he would always respond referring to it using a different name. After several exchanges he responded referring to it as the "Beer Belly B" which I adopted from that point forward.
I guess it's fortunate for the sake of the cool name that it seems to be the less common of the 1909 proofs. It'd be much harder to get someone excited about cherrypicking a "Normal B".