add insult to injury vs intensify

add insult to injury

verb
  • To further a loss with mockery or indignity; to worsen an already unfavourable situation. 

intensify

verb
  • To render more intense 

  • To become intense, or more intense; to act with increasing power or energy. 

How often have the words add insult to injury and intensify occurred in a corpus of books? (source: Google Ngram Viewer )