Sabbath vs Sabbath year

Sabbath

noun
  • A meeting of witches. (Also called a witches' Sabbath, Shabbat, sabbat, or black Sabbath.) 

  • uposatha day 

  • Saturday, observed in Judaism and some Christian denominations as a day of rest and worship. 

  • Among the ancient Jews and Hebrews, the seventh year, when the land was left fallow. 

  • Sunday, observed in most of Christianity as a day of rest and worship. 

Sabbath year

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