sob story vs tearjerker

sob story

noun
  • A sad story, especially one intended to elicit sympathy. 

tearjerker

noun
  • An emotionally charged film, novel, song, opera, television episode, etc., usually with one or more sad passages or ending, so termed because it suggests one is likely to cry during its performance. 

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