gibber vs talk through one's hat

gibber

verb
  • To jabber, talk rapidly and unintelligibly or incoherently. 

noun
  • Gibberish, unintelligible speech. 

  • A balky horse. 

  • A stone or rock, of chalcedony or similar mineral, found strewn over arid regions of inland Australia; a gibber stone. 

talk through one's hat

verb
  • To speak lacking expertise, authority, or knowledge; to invent or fabricate facts. 

  • To assert something as true or valid; to bluff. 

How often have the words gibber and talk through one's hat occurred in a corpus of books? (source: Google Ngram Viewer )