closeness vs propinquity

closeness

noun

  • The state of being close (all senses) 

  • The shortest path between two vertices in a graph 

  • The state of being friends 

  • The state of being secretive 

  • The state of being mean or stingy 

propinquity

noun

  • Nearness or proximity 

  • Affiliation or similarity. 

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