not so hot vs subnormal

not so hot

adj
  • Not very good. 

  • Used other than figuratively or idiomatically: see not, so, hot. 

subnormal

adj
  • Less than normal. 

  • denormal 

noun
  • A person whose abilities are less than normal. 

  • That part of the axis of a curved line which is intercepted between the ordinate and the normal. 

How often have the words not so hot and subnormal occurred in a corpus of books? (source: Google Ngram Viewer )