baths vs piscina

baths

noun
  • A building containing a public swimming pool or shower facilities; originally a place having individual cubicles where people without bathrooms could have a bath. 

piscina

noun
  • A drained basin near a church's altar for the disposal of water from liturgical ablutions. 

  • A basin or tank, especially one for holding fishes or for growing aquatic plants. 

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