Those are not your typical CEC candidate.
To be in the 540+ range you are truely a high skilled worker and you certainly rank high in all evaluation parameters. When you get to the 501 - 510 range, then the quality of the candidates tends to fall, and so on. Plus, this break down from the IRCC is in par with our analysis that 501+ pool is filled with a majority of CEC or Canadian graduates, especially taking into account the number of people added in the last two draws.
Now we know that, on July the 20th, the pool was left with 8,115 candidates with CRS 501+ and the avegare of PNPs is about 700+ per draw, which leads me to believe that the draws have a high chance of returning to the 3,500 level gradually. 2,500 for Federal High Skilled and close to 1,000 for PNPs.