decare vs stremma

decare

noun
  • A unit of surface area equal to 10 ares (that is, 1,000 square metres, 0.10 hectares, or approximately 0.25 acres) 

stremma

noun
  • A Greek unit of land area, now equal to a decare (1,000 m²) but (historical) previously 10,000 square Greek feet. 

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