PM vs dissection

PM

verb
  • To project manage. 

  • To send a private message to (a participant in a chat room, etc.). 

dissection

noun
  • the act of dissecting, or something dissected 

  • a minute and detailed examination or analysis 

  • surgical removal 

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