sex work vs streetwalking

sex work

noun
  • Any job in which sex or eroticism is involved, especially prostitution or pornography. 

  • My mother distributes condoms and outreach materials to those that do sex work for a living in the Tenderloin and Mission. 

streetwalking

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

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