least vs the smallest amount of

least

adv
  • Used for forming superlatives of adjectives, especially those that do not form the superlative by adding -est. 

  • In the smallest or lowest degree; in a degree below all others. 

det
  • The most little; the smallest amount or quantity of something. 

noun
  • Something of the smallest possible extent; an indivisible unit. 

prep
  • At least. 

  • What a stupid white privileged POS I am! Least I call myself out. 

  • 2019 December, Justin Blackburn, The Bisexual Christian Suburban Failure Enlightening Bipolar Blues, page 79 

the smallest amount of

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