Wow! That seems quite a figure. Are you sure of it? Of course, many of those were smokers, so that could account for a lot. I smoked for most of my time in service, especially in Vietnam. But was lucky to have survived a flu I got in early 73 that had me laid out for 8 or 9 days, and afterward realized I hadn't smoked for that long so I needn't ever look back.
At age 40 I declared that I felt I could live at least that much longer. Of course, everyone dies sooner or later. But I hope I make it to that earlier estimate.
Those are some interesting stats you cite.
This is the statistic I found most interesting: 2,709,918 Americans served in Vietnam, this number represents 9.7% of their generation, so 90% of our generation found some other place to be instead of Vietnam.
And yes, I too smoked cigarettes in Vietnam and it was there that I could go for months where the only fun I got out of life was from either smoking cigarettes or scratching my crotch rot.
As for the statistics, they came from:
http://www.nationalvietnamveteransfoundation.org/statistics.htm