98% is TOO high. I would say it is prolly round 90-95% at most.
First of all, he said posters on this board. This board was really set up to formally organize tailgates. It is also mostly male, football fans. I think the people who have never drank would be less than 1% or the HF population over the age of 16?
How many people would you say have NEVER driven after even one drink? I would bet that is very low, maybe 2-5%. Then I would say there are maybe another 5-10% who have set a rule to never drink more than one when driving. Maybe 10-30% of them have actually never gone above that? Everyone else has probably driven drunk.
Don't forget about NyQuil and legal prescription drugs...