self-assured vs self-sustaining

self-assured

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-assured and self-sustaining occurred in a corpus of books? (source: Google Ngram Viewer )