Mrs. Strunk's Earth Science class used an erosion model to investigate the relationship between the slope of a hill, or incline, and the amount of soil that washes off of the incline.

The class increased the slope of the incline from 1 to 5. Then, they poured 100 ml of water down the incline. Finally, they collected the soil from a tray at the bottom of the incline, dried the soil in an oven, and used a balance to find the mass of the soil. The data from their study is shown below.

Based on the graph, more soil is washed away when