Write SQL query to solve given problem: Among the root beer purchased in 2014, what percentage were sold in cans?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(COUNT(CASE WHEN ContainerType = 'Can' THEN RootBeerID ELSE NULL END) AS REAL) * 100 / COUNT(RootBeerID) FROM rootbeer WHERE PurchaseDate LIKE '2014%'