disband vs split up

disband

verb

  • To break up or (cause to) cease to exist; to disperse. 

split up

verb

  • Cease to be together, break apart from the group. 

  • separate, disassociate, cause to come apart. 

adj

  • Divided or separated. 

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