epilogue vs proemium

epilogue

noun
  • A brief oration or script at the end of a literary piece; an afterword 

  • A short speech, spoken directly at the audience at the end of a play 

  • A component of a computer program that prepares the computer to return from a routine. 

  • The performer who gives this speech 

verb
  • To conclude with an epilogue. 

proemium

noun
  • A preface or introduction; a proem. 

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