depreciation vs retroflux

depreciation

noun

  • The decline in value of assets. 

  • The state of being depreciated; disparagement. 

  • 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. 

retroflux

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