kola vs soft drink

kola

noun
  • A tree, genus Cola, bearing large brown seeds ("nuts") that are the source of cola extract. 

  • A nut of this tree. 

soft drink

noun
  • Any carbonated, usually sweet, non-alcoholic drink. (In this sense, juice, milk, tea and coffee are not soft drinks.) 

  • Any non-alcoholic drink. 

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