User blog:History of Grand Theft Auto/GTA VCS: How do i unlock Robbery Business

I'm playing GTA VCS on PSP.

I'm completed From Zero to Hero, I'm unlocked Drug and Smuggling Business, but Robbery is not unlocked, all business (Protection Racket, Loan Shark, Prostition, Drug Dealing and Smuggling) maxed out, but Robbery is locked, how do i unlock this Business