improved vs regenerated

improved

adj
  • That has been made better; enhanced. 

regenerated

adj
  • Physically formed or created again; restored, remade, revived. 

  • Spiritually made again; reborn. 

  • Reprecipitated after chemical treatment, especially in the form of fibres; pertaining to fibres prepared in this way. 

  • Formed by regeneration. 

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