above-board vs perceptible

above-board

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

adv
  • Honestly; openly. 

perceptible

adj
  • Able to be perceived, sensed, or discerned. 

noun
  • Anything that can be perceived. 

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