I found this post by @penguinpablo, it is old but I guess the formulas are still OK.
https://steemit.com/steem/@penguinpablo/til-how-much-steem-is-added-to-the-reward-pool-per-day
And in that article I read this:
So each time a new block has been produced, 1.668 STEEM is added to the reward pool.
Every 3 seconds: 1.668 STEEM
Every minute: 33.354 STEEM
Every hour: 2,001.237 STEEM
Every day: 48,029.695 STEEM
But it varies every day, since the post is two years old I have no idea if the reward pool has increased or decreased. But if the amount is this, circle jerking does take a good percentage of the reward pool, and add the bidbots and very little is left for the rest of us.