balustrade vs townhouse

balustrade

noun
  • A row of balusters topped by a rail, serving as an open parapet, as along the edge of a balcony, terrace, bridge, staircase, or the eaves of a building. 

townhouse

noun
  • A row house or terraced house. 

  • A house in an urban setting. 

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