1SELECT 100.0 * SUM(CASE WHEN Column1 IS NULL THEN 1 ELSE 0 END) / COUNT(*) AS Column1Percent,
2100.0 * SUM(CASE WHEN Column2 IS NULL THEN 1 ELSE 0 END) / COUNT(*) AS Column2Percent,
3100.0 * SUM(CASE WHEN Column3 IS NULL THEN 1 ELSE 0 END) / COUNT(*) AS Column3Percent
4FROM #perc
5