Liam and Chloe each participated in three rounds of a game, earning points in each round. Liam averaged 90 points per round. Chloe scored 10 points more than Liam in the first round, 5 points more in the second round, and 15 points more in the third round. What is the difference between Chloe's average and Liam's average points per round?
5
8
10
12
15