lack vs occupancy

lack

noun
  • A deficiency or need (of something desirable or necessary); an absence, want. 

verb
  • To be short (of or for something). 

  • To be without, not to have, to need, to require. 

occupancy

noun
  • The act of occupying, the state of being occupied or the state of being an occupant or tenant. 

  • The specific use to which something occupied is put. 

  • The period of time during which someone rents or otherwise occupies certain land or premises. 

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