he/she vs who

he/she

pron
  • He or she; singular of they, used as a gender-neutral reference to the third person singular. 

who

pron
  • With antecedent as object: whom. 

  • With antecedent as subject. 

  • What person or people; which person or people; asks for the identity of someone; used in a direct or indirect question. 

  • Whoever, he who, they who. 

det
  • whose 

noun
  • A person under discussion; a question of which person. 

How often have the words he/she and who occurred in a corpus of books? (source: Google Ngram Viewer )