amount vs order of magnitude

amount

noun
  • A quantity or volume. 

  • The number (the sum) of elements in a set. 

  • The total, aggregate or sum of material (not applicable to discrete numbers or units or items in standard English). 

verb
  • To be the same as or equivalent to. 

  • To total or evaluate. 

order of magnitude

noun
  • The class of scale or magnitude of any amount, where each class contains values of a fixed ratio (most often 10) to the class preceding it. For example, something that is 2 orders of magnitude larger is 100 times larger, something that is 3 orders of magnitude larger is 1000 times larger, and something that is 6 orders of magnitude larger is a million times larger, because 10² = 100, 10³ = 1000, and 10⁶ = a million. 

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