custodian vs valet-de-chambre

custodian

noun
  • A person entrusted with the custody or care of something or someone; a caretaker or keeper. 

  • a janitor; a cleaner 

valet-de-chambre

noun
  • The personal servant of a monarch. 

  • A valet. 

How often have the words custodian and valet-de-chambre occurred in a corpus of books? (source: Google Ngram Viewer )