prostitution vs streetwalking

prostitution

noun
  • Engaging in sexual activity with another person in exchange for goods (not necessarily money) or services. 

  • Debasement for profit or impure motives. 

  • Engaging in sexual activity with another person for pay. 

streetwalking

noun
  • The trade of a streetwalker; prostitution that is not tied to a particular brothel or establishment. 

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