Might want to stop at 100
I can tell you from sad experience, you don't want to use a bucket for a step ladder without a piece of wood over the top. When plastic gets old, it gets brittle. Here in the NM sun, it gets old quickly. When your foot goes through the bottom of the bucket, it breaks into several triangular peices that are forced down as your foot goes through. It is kind of like the chinese handcuffs we had as kids, except much more painful. The only way out is to cut the bucket.