basilica vs duomo

basilica

noun
  • A Christian church building having a nave with a semicircular apse, side aisles, a narthex and a clerestory. 

  • A Roman Catholic church or cathedral with basilican status, an honorific status granted by the pope to recognize its historical, architectural, or sacramental importance. 

duomo

noun
  • A cathedral, especially one in Italy. 

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