The list shows the mileage rating (in mpg) for some 2019 vehicles with all-wheel or 4-wheel drive.

11, 13, 14, 14, 15, 15, 15, 16, 16, 16, 17, 17, 17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 20, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 23, 23, 23, 23, 23, 24, 24, 24, 24, 24, 24, 25, 25, 25, 26, 26, 26, 27, 27, 27, 28, 29, 30, 31, 32, 33, 34

Which interval has the greatest frequency?
10–15
15–20
20–25
25–30