digit vs finger's breadth

digit

verb
  • To point at or point out with the finger. 

noun
  • The whole numbers from 0 to 9 and the Arabic numerals representing them, which are combined to represent base-ten numbers. 

  • A narrow extremity of the human hand or foot: a finger, thumb, or toe. 

  • A distinct symbol representing one of an arithmetic progression of numbers between 0 and the radix. 

  • ¹⁄₁₂ the apparent diameter of the sun or moon, (chiefly) as a measure of the totality of an eclipse. 

  • A unit of length notionally based upon the width of an adult human finger, standardized differently in various places and times, (especially) the English digit of ¹⁄₁₆ foot, now equivalent to about 1.9 cm. 

  • Similar or similar-looking structures in other animals. 

finger's breadth

How often have the words digit and finger's breadth occurred in a corpus of books? (source: Google Ngram Viewer )