bai vs lady's maid

bai

noun
  • A people of the Yunnan province of China. 

  • A marshy meadow in sub-Saharan Africa. 

lady's maid

noun
  • A female servant employed by an upper-class woman to attend to her personal needs. 

How often have the words bai and lady's maid occurred in a corpus of books? (source: Google Ngram Viewer )