nonprofessional vs probationer

nonprofessional

noun
  • One who is not a professional; an amateur. 

adj
  • not professional; amateur 

probationer

noun
  • One who is licensed to preach, but not ordained to a pastorate. 

  • One who is on probation. 

  • A chorister in their training period before full admission to a choir, whether or not that period is probationary. 

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