The article in Business Week said that Yamaha has 28% of the North America touring market.
It didn't bother to declare what that number was, either in terms of the size of the segment or in the numbers of units sold by Yamaha.
Each model has a separate numbering sequence, so there are four sequences for the US - 'A' and 'AE' in 49 state and in CA versions, so it isn't all THAT hard to ask for top numbers on the forum and get good data.
I wrote somewhere else that my Canadian 'A' is s/n 112. Who has the highest numbered 'A' in Canada and who has the highest 'AE'?