developed vs youthless

developed

adj
  • Mature. 

  • Not primitive; not third-world. 

  • Containing man-made structures such as roads, sewers, electric lines, buildings, and so on. 

  • Having useful or necessary infrastructure. 

  • Processed and fixed; containing a visible negative (or positive for slide film) image 

  • Advanced, fully formed. 

youthless

adj
  • Devoid of youth; old, aged. 

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