acceptable vs assignable

acceptable

adj
  • worthy, decent, sure of being accepted or received with at least moderate pleasure 

  • Barely worthy, less than excellent; passable. 

assignable

adj
  • Capable of being assigned (all senses). 

  • Capable of being specified or shown. 

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