one brick short of a full load vs shit-for-brains

one brick short of a full load

adj

  • Stupid. 

  • Not mentally sound; insane. 

shit-for-brains

adj

  • Extremely stupid. 

noun

  • An extremely stupid person. 

How often have the words one brick short of a full load and shit-for-brains occurred in a corpus of books? (source: Google Ngram Viewer )