I don't think the concrete came out with most of them because of the method we used to set the posts. Instead of mixing the concrete with sand and water we just dumped a bag in dry, tamped it down and back filled with dirt from the whole. This method used the moisture in the ground to harden the cement but as you can see from the video 7 out of 9 times it didn't adhere to the post itself. I had to go back and dig out the concrete on those 7. They were all hard as a rock with perfect square holes in them.