puerile vs undeveloped

puerile

adj
  • Childish; trifling; silly. 

  • Characteristic of, or pertaining to, a boy or boys; compare puellile. 

undeveloped

adj
  • not developed or used 

  • not built on, unbuilt; not ready for building on 

  • lagging behind others, especially in economic or social matters 

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