inefficient vs lame duck

inefficient

noun
  • A person who cannot or does not work efficiently. 

adj
  • Not efficient; not producing the effect intended or desired; inefficacious 

  • Incapable of, or indisposed to, effective action; habitually slack or unproductive; effecting little or nothing 

lame duck

noun
  • A person or thing that is helpless, inefficient, or disabled. 

  • An elected official who has lost the recent election or is not eligible for reelection and is marking time until leaving office. 

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