skillion vs trillion

skillion

noun
  • A room built against the back of another building, having a separate roof. 

  • Any indefinitely large number. 

trillion

noun
  • A statistic formed by a player playing some number of minutes, but recording no stats. 

num
  • A million million: 1 followed by twelve zeros, 10¹². 

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