Pony Express vs delivery

Pony Express

name
  • A 19th-century mail service delivering messages across North America by means of riders on horseback. 

delivery

noun
  • The act of giving birth 

  • A thrown pitch. 

  • A pitching motion. 

  • The process of throwing a stone. 

  • The administration of a drug. 

  • The item which has been conveyed. 

  • Process of introducing foreign DNA into host cells. 

  • A cross or pass 

  • The act of conveying something. 

  • The manner of speaking. 

  • A ball bowled. 

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