packed lunch vs picnic basket

packed lunch

noun
  • A picnic meal, sandwiches or anything packed and intended to be eaten away from home. 

picnic basket

noun
  • The food in a basket taken to a picnic. 

  • A basket or hamper used to carry food and utensils to a picnic. 

How often have the words packed lunch and picnic basket occurred in a corpus of books? (source: Google Ngram Viewer )