hairdresser vs safety razor

hairdresser

noun
  • A person who cuts or styles hair as an occupation or profession. 

safety razor

noun
  • A razor, designed for safety, that protects the skin from all but the very edge of the blade (as opposed to a straight razor). 

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