matter-of-fact vs plain-speaking

matter-of-fact

adj
  • straightforward, blunt, frank; treating the situation as normal; not embarrassed, coy, or dramatic. 

  • lacking emotion or colour 

  • of, or relating to facts only; literal, realistic 

plain-speaking

adj
  • Synonym of plain-spoken 

How often have the words matter-of-fact and plain-speaking occurred in a corpus of books? (source: Google Ngram Viewer )