en- vs re-

en-

prefix
  • on, onto 

  • an intensifier 

  • caused 

  • in, into 

  • covered 

re-

prefix
  • again, anew 

  • back, backward 

  • a completive or intensification of the base; up, a-, out 

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