disassociate vs join forces

disassociate

verb
  • To separate into smaller discrete units, as with analysis. 

  • To separate; to disunite; to disintegrate; to dissolve. 

  • To separate (oneself); to dissolve one's association with a person, group, or situation. 

join forces

verb
  • To combine labour, to come together, to unite. 

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