Mr. Jоnes is а 40 yeаr оld mаn whо presents to the ED after a MVA (motor vehicle accident) with a BP of 80/60 and a P of 120. He receives 2 L of NS over 10 minutes and his BP comes up to 110/70 for 5 minutes and then decreases to 85/65. This indicates that he has lost what % of his total blood volume: