Players often post their current scores / request advice on where to improve scores in the Monthly Challenge Event threads that are made.
Here is this months thread:
As you can see, there are many players who’ve posted their scores & many who have requested/ benefitted from those scores.
As for your request, I’m not really sure what an “average” score of each stage will show you… Cause mathematically, an average will be “better” for 50% of players and “worse” for the remaining 50%. Looking to the tiers, cut-offs for rewards is 100k players (at the outside)… Looking to the number of players who compete in each week’s tournaments it is >1 million players, I expect that there would be more players involved in the monthly challenge events but we’ll go with 1,000,000 players.
100,000 is 10% of 1,000,000 which is << than the 50% cut off for which the “average score” would be useful.
Just my thoughts.