bird's eye chili vs sweet pepper

bird's eye chili

noun
  • A spicy chili pepper, a cultivar from the species Capsicum annuum, commonly found in Southeast Asia. 

sweet pepper

noun
  • The fruit of a non-spicy cultivar of pepper, Capsicum annuum, marketed in green-, red-, yellow- and orange-skinned varieties. 

How often have the words bird's eye chili and sweet pepper occurred in a corpus of books? (source: Google Ngram Viewer )