abscond vs head for the hills

abscond

verb
  • To evade, to hide or flee from. 

  • To abandon a hive. 

  • To flee, often secretly; to steal away. 

  • To hide, conceal, or absent oneself clandestinely, with the intent to avoid legal process 

  • To hide, to be in hiding or concealment. 

head for the hills

verb
  • To go to a safe place; to seek refuge; to flee. 

  • To travel to a higher elevation, especially to a rural region on vacation. 

How often have the words abscond and head for the hills occurred in a corpus of books? (source: Google Ngram Viewer )