Quiz #25. Congrats to the folks who solved the puzzle by recognizing the difference between “fewer” and “less.” “fewer” is used with things that you can count. “Less” is for uncountable, hypothetical qualities. : “Fewer than twenty,” Less than successful.”
Dr. John’s Grammar quiz #26 “The monthly grammar seminar’s diminishing rate of attendance seems to indicate that many people are disinterested in the subject”.
WriterCare with Dr. John 
More likely they’re simply uninterested in it. And isn’t “rate of” a bit superfluous? (Not to mention “a bit”?)