I rolled these hand-forged metal dice hundreds of times. How fair are they?

Rough metal dice, fresh off the forge! Dice so heavy and clunky and sharp you can ruin tables and kill cheats without brandishing a dagger. But is this ren-faire fun fair play? I decided to put them to the test and see how random they were. I'm not great at math, so I'll just show my method and results and you can do the judging. (more")