let loose vs unrestrict

let loose

verb
  • To free; to release from restraint. 

  • To break wind. 

  • To shout, make a loud sound, or perform a sudden, vehement action; to behave in a raucous, frenzied manner. 

unrestrict

verb
  • To free from restrictions. 

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