Hi! Inspired in this blog, I wanted some data to support my thoughts, so I used codeforces API to plot some graphs. The plots show for each rating what was the average number of problems solved (for lower ratings, there a less users so some unpredictable behavior can happen).
Here, you can see the plot for Codeforces Round #651 (Div. 2):
Note: The x-axis is scalled down, that means that $$$x$$$ is actually $$$100x$$$ (I made in that so that it wont get too poluted).
See other two plots I made:
UPD Here is the plot for Codeforces Round #652 (Div. 2):