mystery tour vs tootle

mystery tour

noun
  • A short-duration outing by coach to a destination that is not revealed in advance 

tootle

noun
  • A trip or excursion. 

  • A soft toot sound. 

verb
  • To transport (someone somewhere). 

  • To make a soft toot sound. 

  • To go (somewhere); to amble aimlessly. 

  • To play (a musical instrument) making such a sound. 

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