basement vs downstairs

basement

noun
  • A floor of a building below ground level. 

  • Last place in a sports conference standings. 

  • A mass of igneous or metamorphic rock forming the foundation over which a platform of sedimentary rocks is laid. 

downstairs

noun
  • The lower floor of a house, at ground level; especially the servants’ quarters. 

  • The genitalia. 

adj
  • Located on a lower floor. 

adv
  • Down the stairs. 

  • In or to hell. 

  • Regarding the genitalia. 

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