sobfest vs tearjerker

sobfest

noun
  • Something sad or moving, especially a film. 

  • An episode of intense crying. 

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 sobfest and tearjerker occurred in a corpus of books? (source: Google Ngram Viewer )