Random Bernie Madoff question

I watched The Wizard of Lies recently and I was curious about how true to history it was.  

I remember seeing various finance internet forums awash in skepticism about his results before it popped.  

How accurate is Bernie Madoff's statement in the movie that his last real trade was around 1985 or so, and everything after that was fake?

What were his returns like when the trades were real vs when they became fake, whatever date that happened?