mid- vs under-

mid-

prefix

  • Amid. 

  • Denoting the middle part. 

  • Occupying a middle position. 

  • Intermediate 

  • During, in the middle of doing something. 

under-

prefix

  • Behind 

  • Beneath, under 

  • Subordinate to 

  • Deficient, below what is correct 

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