petitioner vs solicitant

petitioner

noun
  • Someone who presents a petition to some person in authority. 

  • Someone who presents a petition to a court. 

solicitant

noun
  • One who solicits. 

  • A priest who abused the confessional to solicit women. 

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