musalla vs surau

musalla

noun
  • A place for praying (e.g. outside a mosque); a praying room. 

surau

noun
  • A small room in any public place where Muslims pray. 

  • A small mosque or other Islamic assembly building in parts of Sumatra and the Malay peninsula. 

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