Only 3 turf stadiums in MLB

I was looking at the expanded baseball standings today and it struck me that only 3 teams play on artificial turf in their home ballparks: Twins, Devil Rays, and Blue Jays. It will be down to two teams once the Twins stadium opens in 2010. That's pretty amazing, I bet it was more like half turf, half grass, before the ballpark building era began in the early 90's.