Timbuktu vs bump in the road

Timbuktu

name
  • Any proverbially distant or remote place. 

  • A city in central Mali. 

bump in the road

noun
  • A very small town. 

  • A setback or obstacle, especially one which is relatively minor. 

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