roughness vs upper class

roughness

noun
  • A measure of how rough something is, such as a surface 

  • Abundance, especially of food. 

  • Roughage; coarse fodder. 

  • The property of being rough, coarseness. 

  • Something that is rough; a rough spot. 

upper class

noun
  • the aristocracy 

  • those people at the top of a social hierarchy 

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