Calculating league averages by pitch speed

So I am about to wrap up my calculations but I wanted to ask a question to the readers first. I am going to be posting the BABIP, Strike % and Contact % for all of MLB according to pitch speed. Currently, I have grouped the pitch speeds into 6 categories:

1. 95+
2. 90-94.9
3. 85-89.9
4. 80-84.9
5. 75-79.9
6. 60-74.9

Does anyone see a better way to group the speeds? I would like to do it by pitch type, but I don't have an algorithm to classify ever pitch in one go. For now, I figure this works. The 6th category is the largest range of speeds, but I figured with so little amount of pitches in that range, combined with the fact that those pitches are mostly curves and Jamie Moyer fastballs(kidding), it would make sense.

I will wait a day for any responses and then post the results after that.

Here is a quick tease:

95+ MPH
BABIP: 0.354
Strike %: 64.10%
Contact %: 81.98%

Thanks guys.