Write SQL query to solve given problem: What was the percentage for the answer of "Yes" was given to the question "Has your employer ever formally discussed mental health (for example, as part of a wellness campaign or other official communication)?"?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT CAST(SUM(CASE  WHEN T1.AnswerText LIKE 'Yes' THEN 1 ELSE 0 END) AS REAL) * 100 / COUNT(T1.UserID) FROM Answer AS T1 INNER JOIN Question AS T2 ON T1.QuestionID = T2.questionid WHERE T2.questiontext LIKE 'Has your employer ever formally discussed mental health (for example, as part of a wellness campaign or other official communication)?'