dys- vs sub-

dys-

prefix
  • difficult 

  • painful 

  • unhealthy, harmful 

  • abnormal 

  • poor, deficient 

  • to fail 

  • incorrect 

  • inability, unable 

  • malady, disease 

  • not 

  • bad 

sub-

prefix
  • almost, nearly 

  • subsidiary, secondary 

  • under, beneath 

How often have the words dys- and sub- occurred in a corpus of books? (source: Google Ngram Viewer )