human resources vs worker

human resources

noun
  • The personnel employed in an organization. 

  • The personnel department of an organization, dealing with the recruitment, administration, management and training of employees; abbreviated as HR. 

worker

noun
  • A person who performs labor for a living, especially manual labor. 

  • A nonreproductive social insect, such as ant, bee, termite, or wasp. 

  • A female ant, bee, termite or wasp. 

  • A thread performing one instance of a particular task within a program. 

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