hit someone when they are down vs kick someone when they are down

hit someone when they are down

verb
  • Synonym of kick someone when they are down (“make things worse for someone in a difficult position”) 

kick someone when they are down

verb
  • To make things worse for someone who is going through a difficult time. 

How often have the words hit someone when they are down and kick someone when they are down occurred in a corpus of books? (source: Google Ngram Viewer )