EMS vs ambulance

EMS

noun
  • electronics manufacturing service: a type of OEM (original equipment manufacturer) service. 

  • express mail service: a type of international express mail services. 

  • emergency medical service: an organization, often part of a local government whose purpose is to provide emergency medical care to the public. 

  • environmental management system 

ambulance

noun
  • A mobile field hospital. 

  • An emergency vehicle designed for transporting seriously ill or injured people to a hospital. 

verb
  • To transport by ambulance. 

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