Minnesota vs north forty

Minnesota

name
  • A state in the Upper Midwest region of the United States. Capital: Saint Paul. Largest city: Minneapolis. 

  • A former territory (1849–1858) of the United States, encompassing the modern state and part of the Dakotas. Capital: Saint Paul. 

  • A tributary of the Mississippi River in southern Minnesota. 

  • University of Minnesota, Twin Cities. 

north forty

noun
  • A 40-acre section of land, located in the northernmost part of a farm or ranch. 

  • Any remote place. 

  • Farms, ranches, or agricultural land collectively. 

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