self-confident vs self-sustaining

self-confident

adj
  • Confident in one's own abilities. 

self-sustaining

adj
  • Able to provide for one's own needs without help from others; self-sufficient. 

  • Able to sustain itself without the need for additional fuel. 

  • Opposing or rejecting exterior influence; independent. 

How often have the words self-confident and self-sustaining occurred in a corpus of books? (source: Google Ngram Viewer )