disability vs efficiency

disability

noun
  • An inability imposed on a person by society's failure to accommodate their physical or mental differences from others, as opposed to impairment. 

  • A mental condition causing a difficulty with an intellectual task. 

  • Want of legal qualification to do a thing; legal incapacity or incompetency. 

  • Regular payments received by a disabled person, usually from the state 

  • State of being disabled; deprivation or want of ability; absence of competent physical, intellectual, or moral power, means, fitness, and the like. 

efficiency

noun
  • A one-room apartment. 

  • The extent to which time is well used for the intended task. 

  • The extent to which a resource is used for the intended purpose; the ratio of useful work to energy expended. 

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