drawback vs helpfulness

drawback

noun
  • The inhalation of a lungful of smoke from a cigarette. 

  • A partial refund of an import fee, as when goods are re-exported from the country that collected the fee. 

  • A disadvantage; something that detracts or takes away. 

helpfulness

noun
  • The quality of being helpful. 

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