follow up vs implement

follow up

verb
  • To take further actions remaining after an event; to continue, revisit, or persist; especially, to maintain communication or verify. 

implement

verb
  • To bring about; to put into practice; to carry out. 

noun
  • A tool or instrument for working with. 

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