scrubwoman vs scullery maid

scrubwoman

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

scullery maid

noun
  • A domestic servant, of lowest status, whose job is to wash dishes and do other menial chores. 

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