old town vs slum

old town

noun
  • The historic district of a city or town. 

  • Used other than figuratively or idiomatically: see old, town. 

slum

noun
  • A dilapidated neighborhood where many people live in a state of poverty. 

  • Slumgullion; a meat-based stew. 

  • Inexpensive trinkets awarded as prizes in a carnival game. 

verb
  • To visit a neighborhood of a status below one's own. 

How often have the words old town and slum occurred in a corpus of books? (source: Google Ngram Viewer )