I'm pretty sure we can do this, but got a couple of questions ...
What do you mean by "each period of time"? Do we sum up the hours over an entire employee (for all days), to put them in the "hours worked" bucket, or is it "hours worked over a week (or other timeframe)"?
You say you want the 60 Parameterised and could go down to 50? what happens to people in the 46-60 bucket if the last group is 50+?
If you let me know I'll have a stab!
Awesome, thanks a lot.