FT8 and FT4 sub bands?

Rich N1IXF
 

After the WAE contest this past weekend, I realized that I don't have a clue where the FT8 and FT4 operators congregate.

Are there preferred frequencies / sub-bands for these guys?  For example, I thought they centered their 40M activity around 7074 but found there were also conflicts around 7048/7049.  Felt like I stumbled into the SSTV frequency.

I would like to create an operating aid so I know where this mode has its watering holes on each of the contest bands.  I thought such a chart would exist but I couldn't find one with a quick search. 

Thanks,
Rich N1IXF

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