A fact that you may find interesting is the amount of wine sold on cruise ships.
For the past 20 consecutive years we have failed to sell an average 1 bottle of wine per passenger per cruise, world-wide.
Of course there are other factors at play here:
A certain percentage of cruise passengers are not old enough to purchase wine on most cruise ships.
A certain percentage of cruise passengers drink wine if it is free, but not if they must pay.
Some cruises are very short; others are very long. (Average cruise is 7 days)
Some people do not drink wine - but they do purchase beer and spirits onboard.
Some cruisers have religious or medical reasons for not drinking wine.
A growing number of cruisers today simply cannot afford to buy wine on a cruise.
On some cruise lines, flexible policies result in many pax bringing large quantities of their own wine onboard.
Profit margins on wine sales are far lower than profit margins on beer and spirits; some companies discourage wine sales and concentrate on more profitable beer and spirits sales.
But when you remove the underage passengers from the numbers, we are still not even close to selling an average 1 bottle of wine per passenger per cruise.