Too bad it wasn't a state conviction. Florida requires inmates to serve at least 85% of their sentence.
It may be the type of offense that drives the parole time.
Years ago, right after Obama's policies drove me to sell my business, I worked in a retail store and was robbed by a man with a lengthy history of petty crime. He received a 62 year sentence and would not be allowed to apply for parole for 53 years. This was on Federal charges. Since the guy was in his late 40s he will be over 100 years old before he can apply for parole.