drop in the bucket vs insignificancy

drop in the bucket

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

insignificancy

noun
  • Unimportance, insignificance. 

  • An insignificant person or thing. 

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