celebrate vs mourn

celebrate

verb
  • To perform or participate in, as a sacrament or solemn rite; to perform with appropriate rites. 

  • To extol or honour in a solemn manner. 

  • To honour by rites, by ceremonies of joy and respect, or by refraining from ordinary business; to observe duly. 

  • To engage in joyful activity in appreciation of an event. 

mourn

noun
  • Sorrow, grief. 

  • A ring fitted upon the head of a lance to prevent wounding an adversary in tilting. 

verb
  • To express sadness or sorrow for; to grieve over (especially a death). 

  • To utter in a sorrowful manner. 

  • To wear mourning. 

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