interpolate vs introduce

interpolate

verb
  • To introduce (something) between other things; especially to insert (possibly spurious) words into a text. 

  • During the course of processing some data, and in response to a directive in that data, to fetch data from a different source and process it in-line along with the original data. 

  • To estimate the value of a function between two tabulated points. 

introduce

verb
  • To make (something or someone) known by formal announcement or recommendation. 

  • To cause (someone) to be acquainted (with someone else). 

  • To add (something) to a system, a mixture, or a container. 

  • To bring (something) into practice. 

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