custodian vs herdswoman

custodian

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

  • a janitor; a cleaner 

herdswoman

noun
  • A woman who tends livestock, especially cows and sheep. 

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