pitch a fit vs relax

pitch a fit

verb
  • To become angry, enraged, or upset; to act or react with an outburst, as by shouting, swearing, etc. 

relax

verb
  • To become loose. 

  • To become less severe or tense. 

  • To make something (such as codes and regulations) more lenient. 

  • To calm down. 

  • To relieve (something) from stress. 

  • To make something less severe or tense. 

  • To make something loose. 

  • To become more lenient. 

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