cooler bag vs icehouse

cooler bag

noun
  • Insulated bag used to keep food items cool for a limited amount of time (for example on the way from a grocery store to one's house). 

icehouse

noun
  • A deep cellar or outdoor building used for the storage of ice or snow; sometimes also used to store food at low temperature. 

  • An ice hockey rink. 

  • A cold state in global climate. 

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