precaution vs vigilance

precaution

noun
  • Previous caution or care; caution previously employed to prevent misfortune or to secure good 

  • A measure taken beforehand to ward off evil or secure good or success; a precautionary act. 

verb
  • To warn or caution beforehand. 

  • To take precaution against. 

vigilance

noun
  • Alert watchfulness. 

  • Close and continuous attention. 

How often have the words precaution and vigilance occurred in a corpus of books? (source: Google Ngram Viewer )