Requesting US cask ale production statistics

To the US beer community: a request for assistance.

Would anyone have statistics on annual production volume of cask ale in the US?

Alex Hall regularly updates his —labor of love— website with names of bars and restaurants (including brewpubs) that serve cask ale.

But to analyze the growth of cask ale in the US, I'm looking for the names and annual cask ale production volume of those breweries and brewpubs that produce cask ale (and kellerbier).

Please contact me by leaving a comment below or sending an email here.