Timbuktu vs off the beaten track

Timbuktu

name
  • Any proverbially distant or remote place. 

  • A city in central Mali. 

off the beaten track

prep
  • In a place or places not commonly visited. 

  • To a place or places not commonly visited. 

How often have the words Timbuktu and off the beaten track occurred in a corpus of books? (source: Google Ngram Viewer )