preoccupancy vs preoccupation

preoccupancy

noun
  • The act or right of taking possession before another. 

preoccupation

noun
  • The act of occupying something before someone else. 

  • The state of being preoccupied or an idea that preoccupies the mind; enthrallment. 

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