lean on vs rule with an iron hand

lean on

verb
  • Used other than figuratively or idiomatically: see lean, on. 

  • To put pressure on; to attempt to compel a person to do something; to exert influence on. 

  • To depend upon for support; to require assistance from. 

  • To criticize or reprimand for the purpose of changing behavior. 

rule with an iron hand

How often have the words lean on and rule with an iron hand occurred in a corpus of books? (source: Google Ngram Viewer )