laager vs refugee camp

laager

noun
  • A defensive encampment encircled by wagons, especially by South African Boers. 

  • A temporary formation of armoured vehicles for resupply. 

verb
  • To arrange in a circular formation for defence. 

  • To camp in a circular formation. 

refugee camp

noun
  • A camp where refugees seek shelter. 

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