dishwasher vs washtub

dishwasher

noun
  • A machine for washing dishes. 

  • A European bird, the wagtail. 

  • Someone who washes dishes, especially one hired to wash dishes in a restaurant. 

  • A bird, the restless flycatcher (Myiagra inquieta). 

washtub

noun
  • A tub used for washing clothes. 

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