Well, firstoff there was a long thread about this very subject a short while ago.

Second, I really don't think that the simplistic approach will do, as rate also depends on pH and buffer capacity as well as sulfite content. And, these are also affected by temperature.

I personally think that the tables are better than factors. In addition, where are ascorbic acid developers, phenidone developers, dimezone developers and etc.... So simple data such as you post are too incomplete to be truly useful.

Just my $0.02! (for you non US readers - my two cents worth)

PE