I think it varies wildly by console and even by year within a given console's lifespan.

I mean, There are systems that saw close to 1K games over the years while others didn't crack 100

If I had to guess (read: based on nothing), I'd say the PS2 probably had the most games per year. I'd also guess that, and maybe PS1 are the only ones to hit an average of 200 per year.