malaise vs unhappiness

malaise

noun
  • An ambiguous feeling of mental or moral depression. 

  • A feeling of general bodily discomfort, fatigue or unpleasantness, often at the onset of illness. 

  • Ill will or hurtful feelings for others or someone. 

unhappiness

noun
  • The feeling of not being happy 

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