bellboy vs errand boy

bellboy

noun
  • A male worker, usually at a hotel, who carries luggage and runs errands. 

errand boy

noun
  • A male employed to run errands. 

  • Someone in a responsible position who performs relatively menial tasks for a senior manager. 

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