Lord Provost vs mayoress

Lord Provost

noun
  • The civic head of certain cities in Scotland, having a role similar to that of mayor. 

mayoress

noun
  • A daughter or female friend of a male mayor chosen by him to hold the title mayoress. 

  • The wife of a (male) mayor. 

  • A female mayor. 

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