crosswalk vs zebra crossing

crosswalk

noun
  • A point designated for pedestrians to cross a street. 

  • A mapping between equivalent elements (fields) in different database schemas. 

verb
  • To map equivalent elements (fields) in different database schemas. 

zebra crossing

noun
  • A pedestrian crossing featuring broad white stripes painted parallel to the street. 

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