angular mil vs fingerbreadth

angular mil

noun
  • A unit of angular measurement equal to 1/6400 of a complete circle. At 1000 metres one mil subtends about one metre (~0,98 m). Also 1/6000 and 1/6300 are used in other countries. 

fingerbreadth

noun
  • A (usually approximate and informal) unit of measurement based upon the radial width of the human finger. 

How often have the words angular mil and fingerbreadth occurred in a corpus of books? (source: Google Ngram Viewer )