petrol pump vs service station

petrol pump

noun
  • A device at a petrol station that dispenses petrol. 

  • A filling station. 

service station

noun
  • a filling station, gas station or petrol station; a facility selling fuel for road motor vehicles 

  • a service area 

How often have the words petrol pump and service station occurred in a corpus of books? (source: Google Ngram Viewer )