convenience vs work in

convenience

verb
  • To make convenient 

noun
  • Any object that makes life more convenient; a helpful item. 

  • The quality of being convenient. 

  • A convenient time. 

work in

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

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

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

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