disappear vs do a moonlight flit

disappear

verb
  • To make vanish; especially, to abduct and murder surreptitiously for political reasons. 

  • To go missing; to become a missing person. 

  • To go away; to become lost. 

  • To vanish. 

do a moonlight flit

How often have the words disappear and do a moonlight flit occurred in a corpus of books? (source: Google Ngram Viewer )