Write SQL query to solve given problem: How old was the awardee when he/she won the first-ever award for Outstanding Voice-Over Performance in Primetime Emmy Awards?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T2.year - CAST(SUBSTR(T1.birthdate, 1, 4) AS int) AS age FROM Person AS T1 INNER JOIN Award AS T2 ON T1.name = T2.person WHERE T2.award = 'Outstanding Voice-Over Performance' AND T2.organization = 'Primetime Emmy Awards' AND T2.result = 'Winner';