Calculate the percentage of the app user IDs under Industry tag category.
percentage = DIVIDE(MULTIPLY(CONCAT(COUNT(app_id WHERE category = 'Industry tag'), 100), COUNT(app_id)),'%');
SELECT SUM(IIF(T1.category = 'Industry tag', 1, 0)) * 100 / COUNT(T2.app_id) AS per FROM label_categories AS T1 INNER JOIN app_labels AS T2 ON T2.label_id = T1.label_id