impresario vs showman

impresario

noun
  • A manager or producer in the entertainment industry, especially music or theatre. 

showman

noun
  • A person who produces or presents shows as a profession, especially the proprietor, manager, or MC of a circus or variety show. 

  • A person skilled in dramatic or entertaining presentation, performance, or publicity. 

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