epi- vs under-

epi-

prefix

  • Above, over, on 

  • In addition to 

  • Denotes an epimeric form 

under-

prefix

  • Beneath, under 

  • Behind 

  • Subordinate to 

  • Deficient, below what is correct 

How often have the words epi- and under- occurred in a corpus of books? (source: Google Ngram Viewer )