confuse vs tell why

confuse

verb
  • to puzzle, perplex, baffle, bewilder (somebody); to afflict by being complicated, contradictory, or otherwise difficult to understand 

  • To mix up, muddle up (one thing with another); to mistake (one thing for another). 

  • To mix thoroughly; to confound; to disorder. 

  • To be confused. 

tell why

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