above-board vs sincerely

above-board

adv
  • Honestly; openly. 

adj
  • In open sight; without trick, concealment, or deception. 

sincerely

adv
  • In a sincere or earnest manner; honestly. 

  • A conventional formula for ending a letter, used when the salutation addresses the person for whom the letter is intended by his or her name. 

How often have the words above-board and sincerely occurred in a corpus of books? (source: Google Ngram Viewer )