Chopper vs SEAT

Chopper

noun

  • A British Rail Class 20 locomotive. 

SEAT

noun

  • Single engine air tanker. 

  • An automobile from Sociedad Española de Automóviles de Turismo 

name

  • Sociedad Española de Automóviles de Turismo, a Spanish automobile manufacturer. 

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