depreciation vs worm in the apple

depreciation

noun
  • The state of being depreciated; disparagement. 

  • The decline in value of assets. 

  • The measurement of the decline in value of assets. Not to be confused with impairment, which is the measurement of the unplanned, extraordinary decline in value of assets. 

worm in the apple

noun
  • A serious flaw in something otherwise good; a problem that ruins everything else. 

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