modify vs rubify

modify

verb
  • To be or become modified. 

  • To change part of. 

  • To set bounds to; to moderate. 

  • To qualify the meaning of. 

rubify

verb
  • to redden; to become red 

  • to make red; to cause to redden 

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