You are confusing volumes of liquid with alcoholic quantity, whereas you should be referring to the volume of alcohol within the drink and the quantity being drunk. Where you drink is pretty irrelevant in the early stages of alcoholism, although dependency can affect this at some stage.
Rather than trying to bombard him with factoids, why not try to emphasise how this is affecting you and your relationship. Alcoholism isn�t a laughing matter really and can destroy the lives of those who are alcoholic as well as those around them. See here for info:
http://www.d-2k.co.uk/factfiles_html/pdfs/Alco holFacts.pdf
There is lots of free help available out there if this is a serious issue.