bell pepper vs red pepper

bell pepper

noun
  • Capsicum annuum, an edible spicy-sweet fruit, originating in the New World. 

red pepper

noun
  • Spicy pepper. 

  • A red-colored, ripe, bell or sweet pepper. Unripe peppers of this variety are green and edible but not as sweet. 

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