It really varies a lot from species to species. For those that mature in under a year, expect four or five during the first year of life then nothing after that. Large tropical scorpions may molt a few times the first year but will slow down as they approach maturity.
Keep in mind that scorpions, unlike tarantulas, do not molt once they reach maturity.
Regarding H. arizonensis, the success rate of rearing them in captivity is so poor that not many people (if any) know what a juvenile's "normal" molting schedule is like. The vast majority that people keep are WC adults.
Also, molting frequency can vary greatly with temperature -- you can keep a scorpion from molting simply by housing it below its developmental threshold. (But then it never grows and eventually dies.)
