infix vs work in

infix

verb
  • To instill. 

  • To insert a morpheme inside an existing word. 

noun
  • A morpheme that always appears between other morphemes in a word, such as -i- and -o- in English (i.e. an interfix). 

  • A morpheme inserted inside an existing word, such as -bloody- in English. 

work in

verb
  • Used other than figuratively or idiomatically: see work, in. 

  • To find time or space for, amid other things. 

  • To work out using a machine in between the sets of someone who is already using that machine. 

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