unbar vs unstrap

unbar

verb
  • To unlock or unbolt a door that had been locked or bolted with a bar. 

  • To remove an impediment that obstructs the passage of (someone or something). 

  • To remove a prohibition. 

unstrap

verb
  • To loosen or remove the straps from (something). 

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