An average is not related to artistic aspects of the data and so can't be a derivative in the copyright sense (based on international law - one of the principle Conventions is fully titled "the Berne convention for the protection of literary and artistic laws", that's because copyright protects literary and artistic works).

Provided you have rights to access a body of statistics, then copyright has nothing to say -- save overreaching national caselaw (!) -- on your derivation of mathematical, technical, or scientific data from that work.

But a contractual clause, in general, doesn't care about copyright; of you've contracted not to derive data from a work then that's orthogonal to copyright.

IANA(IP)L, this is my opinion and unrelated to my employment.