What difference does Anderson observe between her experiences in ninth grade and her experiences in tenth grade?

Anderson paints a dark portrait of her ninth grade year. It was only a matter of days before she started her ninth grade year of high school that her boyfriend raped her. So when she started ninth grade, she soon fell into self-medicating with marijuana as a way to numb her feelings. In tenth grade, however, Anderson had taken the gym teacher’s advice to join sports teams and had felt more agency in her own life as a result.