make a big thing about vs understate

make a big thing about

understate

verb
  • To state (something) with a lack of emphasis, in order to express irony. 

  • To state (something) with less completeness than needed; to minimise or downplay. 

  • To state a quantity that is too low. 

How often have the words make a big thing about and understate occurred in a corpus of books? (source: Google Ngram Viewer )