To answer your question, somewhere around 100 hrs total, I guess !
I BTW consider myself having been probably most safe just after passing my PPL - being really cautious due to my awareness of my own lack of experience. Likewise, I consider myself having been never as "fit" at that time, having flown 50-ish hours in a matter of a few months.
Looking at the graph above, there's a peak at around 500 hrs, and I'm guessing that's due to people becoming over-confident, perhaps relaxing procedures due to having a lot of routine.