in this world, people can see the level of someone's anger

You have a friend named Vinn, his anger level is always 0%, you have done everything to make him angry but he always doesn't get angry. You once saw Vinn being teased by someone and his anger level rose to 16%, finally you tried to tease Vinn and made him angry but he still wasn't angry with you. One day you were with your friend, you got splashed with water by your friend, and it made you upset but it was just a joke. Suddenly your friend's face looks scared, You look back and see Vin's anger level going ????% that's dangerous!