hers vs his

hers

pron
  • That which belongs to her; the possessive case of she, used without a following noun. 

his

pron
  • That which belongs to him; the possessive case of he, used without a following noun. 

det
  • Belonging to him. 

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