sabbatical vs shore leave

sabbatical

noun
  • An extended period of leave from a person's usual pursuits. 

adj
  • Relating to the Sabbath. 

  • Relating to a sabbatical. 

shore leave

noun
  • Free time given to sailors of the military navy when they are off duty and allowed to disembark and spend time on land. 

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