I hope I will not embarrass you, I am asking this question in regards to a trivia question which is, how many breaths a day does a healthy adult take.
Depends on activity levels. Deep resting breath-rate could be three but as a practical matter perhaps 6. Eight is still good but not great. Pauses are critical. Intense activity could be 60 per minute. See the BREATHING TESTS for more insight on all that.
Beyond that the longer, slower, effortlessly deeper breaths taken in most any activity would seem to be superior than faster ones. I repeat effortlessly because many force the breath which force actually restricts the deepest easiest breath. Breathing Improvement program