make a killing vs make out

make a killing

verb
  • To win or earn a large amount of money. 

make out

verb
  • To manage, get along; to do (well, badly etc.). 

  • To discern; to manage to see, hear etc. 

  • To draw up (a document etc.), to designate (a cheque) to a given recipient, payee. 

  • To represent; to make (something) appear to be true. 

  • To embrace and kiss passionately. 

  • To engage in heavy petting or sexual intercourse. 

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