During which ages did Sally grow the MOST in height?

Ages 2 to 3 represents the steepest part of the graph. During ages 1 to 2, Sally grew by approximately 8 inches; during ages 2 to 3, she grew by approximately 15 inches; during ages 3 to 4, she grew by approximately 5 inches; and during ages 4 to 5, she grew by approximately 10 inches. Therefore, Sally grew the most during ages 2 to 3, when she grew approximately 15 inches.