drop in the bucket vs small beer

drop in the bucket

noun
  • Something of little importance, especially an inconsequential effort or action as compared to a huge problem. 

small beer

noun
  • Something that is of relatively little importance. 

  • Beer with a low alcoholic content, usually between 0.5% and 2.8%. 

  • Used other than figuratively or idiomatically: see small, beer. 

How often have the words drop in the bucket and small beer occurred in a corpus of books? (source: Google Ngram Viewer )