You may have already seen the Kindle Unlimited pool for August ($23.3 million).
In case you’re curious, though, The Digital Reader compiled a list of previous months’ funding pools, back to July 2014.
The August 2018 figure is an increase from previous months, though the per-page rate hasn’t moved much: $0.004491 in August, from $0.004460 in June and $0.00454 in May.