inadequate vs runt of the litter

inadequate

noun

  • An individual who is inadequate. 

adj

  • Not adequate; not fit for the purpose 

runt of the litter

noun

  • the smallest and weakest person in a group, especially a group of siblings 

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