in one's (best) interests vs promising

in one's (best) interests

promising

noun

  • The act of making a promise. 

adj

  • Showing promise, and likely to develop in a desirable fashion. 

  • a promising young apprentice 

  • Encouraging and inspiring confidence. 

How often have the words in one's (best) interests and promising occurred in a corpus of books? (source: Google Ngram Viewer )