Write SQL query to solve given problem: What is the highest lake area coverage of a country?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.Area * 100  / T3.Area FROM located AS T1 INNER JOIN lake AS T2 ON T1.Lake = T2.Name INNER JOIN country AS T3 ON T3.Code = T1.Country ORDER BY T2.Longitude DESC LIMIT 1