free rider vs moocher

free rider

noun
  • One who obtains benefit from a public good without paying for it directly. 

  • A worker at an open shop who is able to enjoy the benefits negotiated by a union without being a member of the union. 

  • Someone who obtains goods or services legally without paying. 

moocher

noun
  • A person having a tendency to take advantage of the help of others, especially if making little effort to help themselves. 

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