Task: Question Understanding
Input (English): Passage: Lawrence followed his father into a military career. His father was General Charles John Lawrence and is said to have served in Flanders under John Churchill, 1st Duke of Marlborough. Charles Lawrence's earlier life is obscure. He was commissioned in the 11th Regiment of Foot and served in the West Indies from 1733 until 1737. He then served in the War Office. He was made lieutenant in 1731 and then captain in 1745. He was wounded while serving with the 54th Foot in the battle of Fontenoy in 1745.
Question: How many years did Charles serve in the West Indies?
Output (English): number