powers that be vs proletariat

powers that be

noun
  • The holders of power or the authorities in a given situation, especially if seen as being faceless or unreasonably bureaucratic. 

proletariat

noun
  • Wage earners collectively, excluding salaried workers; people who own no capital and depend on their labour for survival; the working class, especially when seen as engaged in a class struggle with the bourgeoisie (“the capital-owning class”). 

  • The lowest class of society; also, the lower classes of society generally; the masses. 

  • The lowest class of citizens, who had no property and few rights, and were regarded as contributing only their offspring to the state. 

How often have the words powers that be and proletariat occurred in a corpus of books? (source: Google Ngram Viewer )