eldern vs swaybacked

eldern

adj
  • Elder; elderly; aged; old. 

  • Not new; old; ancient. 

swaybacked

adj
  • Old. 

  • Having sagged or hollow surface. 

  • Having a sagged back. 

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