detain vs impede

detain

verb
  • To keep back or from; to withhold. 

  • To put under custody. 

  • To seize goods for official purposes. 

  • To keep someone from proceeding by holding them back or making claims on their attention. 

impede

verb
  • To get in the way of; to hinder. 

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