Sherpa vs skycap

Sherpa

noun
  • A member of a particular Himalayan ethnic group living in Nepal and Tibet, known especially as mountaineers. 

  • A high-ranking government official who works tirelessly in the background to conclude the text of an official communiqué, typically from a G7 or G20 summit. 

name
  • The Southern Tibetan language of these people. 

skycap

noun
  • A porter at an airport. 

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