custodian vs scrubwoman

custodian

noun
  • a janitor; a cleaner 

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

scrubwoman

noun
  • A woman employed to do general housework, such as cleaning a house or office. 

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