hirself vs themself

hirself

pron
  • Hir, themself; gender-neutral third-person singular object of a verb or preposition that also appears as the subject, coordinate with gendered himself and herself. 

  • Sie; an intensive repetition of a gender-neutral subject, often used to indicate exclusiveness of that person as the only satisfier of a predicate. 

themself

pron
  • The reflexive form of they, the third-person singular personal pronoun. The single person previously mentioned, as the object of a verb or following a preposition (also used for emphasis). 

  • Synonym of themselves (the third-person plural). 

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