Question: Among all the root beers sold in 2014, what is the percentage of the root beers produced by the brewery AJ Stephans Beverages?
SQL: SELECT CAST(COUNT(CASE WHEN T3.BreweryName = 'AJ Stephans Beverages' THEN 1 ELSE NULL END) AS REAL) * 100 / COUNT(T1.BrandID) FROM rootbeer AS T1 INNER JOIN `transaction` AS T2 ON T1.RootBeerID = T2.RootBeerID INNER JOIN rootbeerbrand AS T3 ON T1.BrandID = T3.BrandID WHERE T2.TransactionDate LIKE '2014%'