debark vs detrain

debark

verb
  • To disembark. 

  • To devocalize (a dog). 

  • To unload goods from an aircraft or ship. 

  • To remove the bark from a tree, especially one that has been felled. 

detrain

verb
  • To exit from a train; to disembark 

  • to reduce one's training, particularly during the offseason, in preparation for a cycle of retraining. 

  • to remove a passenger or passengers from a train; to evacuate passengers from a train. 

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