If you only wanted to track the boomers, then here are those numbers.
The very first boomers (ages 21 and 22) voted in 1968, that year the under 30 vote gave democrats 47%, by 1972 boomers filled most of the 18-29 pool and democrats got 46% of that vote, in 1976 democrats got 51% (the 18-29 were all boomers), and in 1980 they got 44% (again, all boomers), and in 1984 democrats won 40% of the (almost all boomer) 18-29 year old vote, in 1988 it was 47% for democrats (almost half boomers), by 1992 the boomers had left the 18-29 year old demographic except for the single years worth of 29 year olds, that signalled the end of the young being conservative.
In 1992, without the boomers (except for the 29 year olds)the 18-29 year old vote went 34% Republican, in 1996 with zero boomers, they went 34% Republican, 2000 46% Republican, 2004 47% Republican, and in 2008, their worst year ever, 32% Republican.