forefinger vs trigger finger

forefinger

noun

  • The index finger: the first finger next to the thumb. 

trigger finger

noun

  • the forefinger 

  • a finger used in pulling the trigger of a firearm 

  • difficulty encountered in finger flexion or extension caused by the narrowing of the sheath that surrounds that finger's tendon 

How often have the words forefinger and trigger finger occurred in a corpus of books? (source: Google Ngram Viewer )