Cap vs Ish

Cap

name
  • A nickname for a man generally. 

  • A nickname for the captain of a team, ship, etc. 

Ish

name
  • A diminutive of the male given name Ishmael. 

  • A diminutive of the female given name Ishani. 

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