In 1749, Britain and France agreed to keep the island neutral, but Britain took control after 1763, prompting France to capture the island in 1781, then Britain to recapture the island in 1793.  The population in 1771 was 5,084, of which only 243 were white and 4,716 were slaves.  In 1791 the population was 15,020, of which 541 were white and 14,170 were slaves.  There were then 37 sugar factories, 99 cotton factories, and 4 coffee factories.  After nutmeg was discovered in 1768, 40 nutmeg plantations were started.  The island became a British acquisition for good in 1802, with a ratified treaty in 1814.
Question: How many years after Britain took control of the island did France capture it?
Answer: 18