cast aspersions on vs disparage

cast aspersions on

disparage

verb
  • To ridicule, mock, discredit. 

  • To dishonor by a comparison with what is inferior; to lower in rank or estimation by actions or words; to speak slightingly of; to depreciate; to undervalue. 

How often have the words cast aspersions on and disparage occurred in a corpus of books? (source: Google Ngram Viewer )