disconcert vs throw for a loop

disconcert

verb

  • To upset the composure of. 

  • To bring into confusion. 

  • To frustrate, discomfit. 

noun

  • A state of disunion. 

throw for a loop

verb

  • Synonym of knock for a loop 

How often have the words disconcert and throw for a loop occurred in a corpus of books? (source: Google Ngram Viewer )