mayday vs yell

mayday

noun
  • An international distress signal used by shipping and aircraft. 

yell

noun
  • A shout. 

  • A phrase to be shouted. 

verb
  • To tell someone off in a loud and angry manner. 

  • To convey by shouting. 

  • To shout; holler; make a loud sound with the voice. 

adj
  • dry (of cow) 

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