ammunition vs tear gas

ammunition

verb
  • To supply with ammunition. 

noun
  • Articles used in charging firearms and ordnance of all kinds; as powder, balls, shot, shells, percussion caps, rockets, etc. 

  • Arguments and information that can be used against the other party in a conflict. 

tear gas

verb
  • To use tear gas. 

noun
  • Any lachrymatory, non-lethal chemical compound that causes the eyes to sting and water and/or irritates the respiratory system, mostly used for controlling crowds during riots or as self-defense. 

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