not the sharpest knife in the drawer vs thick as champ

not the sharpest knife in the drawer

noun
  • Lacking in intelligence; dimwitted. 

thick as champ

adj
  • Very ignorant or foolish, sullen or in a bad temper. 

How often have the words not the sharpest knife in the drawer and thick as champ occurred in a corpus of books? (source: Google Ngram Viewer )