From Jan to Aug with 5460 miles I have had 24 flats. That comes out to a flat every 227.4 miles per flat.
I run the Michelin DYNAMIC 700 x 23c. When they are new I had no flats. But after 300 to 350 miles you start geting flats. The tires are rated for 2200 miles. But I ride them hard and the roads around here are not that great.