by CraigTP. (Please note that some users do not have valid "ages"!)
Q&A about the site for professional and independent game developers
-- Age Distribution of Stack Overflow Contributors. -- by CraigTP. -- (Please note that some users do not have valid "ages"!) WITH Breakdown AS (SELECT count(*) AS AgeCount, Age, Band = CASE WHEN Age <= 10 THEN '1-10' WHEN Age > 10 AND Age <= 15 THEN '11-15' WHEN Age > 15 AND Age <= 20 THEN '16-20' WHEN Age > 20 AND Age <= 25 THEN '21-25' WHEN Age > 25 AND Age <= 30 THEN '26-30' WHEN Age > 30 AND Age <= 35 THEN '31-35' WHEN Age > 35 AND Age <= 40 THEN '36-40' WHEN Age > 40 AND Age <= 45 THEN '41-45' WHEN Age > 45 AND Age <= 50 THEN '46-50' WHEN Age > 50 AND Age <= 55 THEN '51-55' WHEN Age > 55 AND Age <= 60 THEN '56-60' WHEN Age > 60 AND Age <= 65 THEN '61-65' WHEN Age > 65 AND Age <= 70 THEN '66-70' WHEN Age > 70 THEN '71+' END from Users WHERE Age IS NOT NULL GROUP BY Age ) SELECT SUM(AgeCount) AS NumberOfUsers, PercentageOfUsers = ROUND((CAST(SUM(AgeCount) as decimal) / CAST((SELECT SUM(AgeCount) FROM Breakdown) as decimal) * 100), 2), Band AS AgeBracket FROM Breakdown GROUP BY Band ORDER BY Band