Rough estimate is about 70 times now. About 40 trips have been in the last 3 years since our daughter turned a year old.
First trip was in the summer of 1977 at age 12. We took a summer trip each year through high school. I went to college at FSU (about 4 hours away), so I made the trip down quite a bit (about 4-5 times a year). That was 1983-1987. During grad school and thereafter (the 1990's) my frequency dropped (darned work!).
Since our daughter turned 1 in January 1999, we go up about a dozen times a year. It's a 7 hour round trip drive. We mostly do long 3 or 4 day weekends, but do an 8 night trip once a year in January and a 5 night trip in September.