For the top two deciles you have 15 and 74 drinks/week:

https://www.washingtonpost.com/wp-apps/imrs.php?src=http://w...

If we take oz of hard liquor, which is set at 40% alcohol, we get:

74 * 52 * .4 / 128 [oz/gallon] = 12.025 gallons of pure alcohol in a year

And:

15 * 52 * .4 / 128 = 2.44 gallons of pure alcohol

I think the folks who are really going hard pump the average (mean) up a lot.