overstrain vs peter out

overstrain

noun
  • excessive strain 

verb
  • To subject to an excessive demand on strength, resources, abilities, or the imagination. 

peter out

verb
  • Synonym of peter (“originally (mining), of a vein of ore: to be depleted of ore; now (generally), to diminish to nothing; to dwindle, to trail off”) 

How often have the words overstrain and peter out occurred in a corpus of books? (source: Google Ngram Viewer )