green pepper vs sweet pepper

green pepper

noun
  • A green variety of dried peppercorn, made from the unripe berries by treating them in a manner that retains the green colour. 

  • The green, unripe, form of the sweet bell pepper. Popular in cooking, especially Italian cuisine. The unripe bell pepper is green and generally changes to other colors as it matures, cultivars exist for red, orange, yellow and other shades. 

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 green pepper and sweet pepper occurred in a corpus of books? (source: Google Ngram Viewer )