chaparral vs primeval forest

chaparral

noun
  • A region of shrubs, typically dry in the summer and rainy in the winter. The coast of the Mediterranean is such a region. 

  • The foliage of creosote bush, Larrea divaricata, when used as a medicinal herb. 

primeval forest

noun
  • A forest unaffected by humans, typically containing large live trees, large dead trees, and large logs. 

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