mope vs run out of steam

mope

verb
  • To carry oneself in a depressed, lackadaisical manner; to give oneself up to low spirits; to pout, sulk. 

  • To make spiritless and stupid. 

noun
  • A bottom feeder who "mopes" around a pornography studio hoping for his big break and often does bit parts in exchange for room and board and meager pay. 

  • The act of moping 

run out of steam

verb
  • To run out of energy or motivation. 

How often have the words mope and run out of steam occurred in a corpus of books? (source: Google Ngram Viewer )