usefully vs without prejudice

usefully

adv
  • In a useful manner; in a way that achieves something 

without prejudice

prep
  • Not affecting nor considering other possibly related issues. 

  • Without affecting a legal interest. 

  • A term used to allow a statement or proposal in communications, while allowing the party to return to their original position without being impeded by the described statement or proposal. 

How often have the words usefully and without prejudice occurred in a corpus of books? (source: Google Ngram Viewer )