We looked at over 190,000 high school wrestlers in the 2015-2016 season and found an average fat percentage at certification of 16.6%.  By minimum weight class, the average fat percentage is:

No big surprises here, just a good set of numbers to have handy.  We'll take another look next season.

Addendum (4/15/16)

We also went back and looked at 2014-2015.  Slightly smaller sample size, but otherwise very similar:

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