GI vs infantry

GI

noun
  • A member of the U.S. military. 

  • One who is demanding and strict, in the manner of a stereotypical member of the military. 

verb
  • To clean aggressively. 

infantry

noun
  • A regiment of infantry 

  • Soldiers who fight on foot (on land), as opposed to cavalry and other mounted units, regardless of external transport (e.g. airborne). 

  • The part of an army consisting of infantry soldiers, especially opposed to mounted and technical troops 

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