I've had more punctures on Angel GT/GT IIs than Road 6s, per mile. Very roughly around 1 puncture every 2 tyres, so once every 12-14,000 miles. Having said that, there's no pattern to it that I can discern - nothing like 'Ooo rough road' followed by 'Darn it, a puncture.' They're always random acts of deflation.
My IAM associates do say 'Well, I was taught not to ride down the centre of my lane because of the all bits that drop off cars and don't get swiped to the side of the road.' and variations on that theme.
They have a point, and it causes me to think (but no solid evidence) that I've had more punctures in the past 10 years, but I'll accept a safer position and possible punctures than a riskier position. Tyres are cheaper to replace than legs.