impenitent vs unapologetic

impenitent

adj
  • Not penitent; specifically (Christianity), not repenting of one's sins; unrepentant. 

noun
  • One who is not penitent. 

unapologetic

adj
  • Not apologetic for having said or done something that causes actual or potential harm, especially when being apologetic would be appropriate. 

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