[KolenCh]

It is low probably because the meeting degree they are having already take up most of the time, and may also be because for those better equipped in math they are in research that requires more sophisticated level of math already (ie self selection).

This is extrapolated from my experience in CMB data analysis. People with better math training probably are doing theoretical work via simulation instead. Some, but not all, papers involving CMB data analysis struggles to present their research mathematically, or may perform some statistical analysis in a very naïve way.