I am reading IELTS band 9 writing samples, and I came across this sentence:
"Passenger numbers peak 3 times during the day. For example, the number at 6am is 480, rising to 690 by 8am before falling again. There is then a peak of 700 at midday, followed by an afternoon decline to a low of 230 at 4pm. A third spike is at 6pm, reaching 670 before tailing off."
This is from the book Get IELTS Band 9 Writing Task One by Cambridge Consultants
Since it has been mentioned before that there are three peaks, shouldn't the article the be used here?
Eagerly waiting for your replies!