netty vs portapotty

netty

noun
  • Any other place or fixture used for urination and defecation: a lavatory; a toilet. 

  • An outhouse: an outbuilding used as a lavatory. 

adj
  • Netted: made of or employing a net. 

  • Netlike. 

portapotty

noun
  • A portable restroom. 

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