Compare each top editor's total edits against the overall average: How much more than average as percentage

SQL

SET @Average_edits = (
    SELECT AVG(Total_edits) AS Average_edits
    FROM (
        SELECT 
            r.rev_actor AS EDITOR_ID,
            a.actor_name,
            COUNT(r.rev_id) AS TOTAL_EDITS
        FROM 
            revision AS r
        JOIN 
            actor AS a ON r.rev_actor = a.actor_id
        WHERE 
            r.rev_timestamp BETWEEN DATE_FORMAT(CURDATE() - INTERVAL 2 MONTH, '%Y-%m-01') 
                            AND LAST_DAY(CURDATE()) 
        GROUP BY 
            r.rev_actor
    ) AS NEW
);

SELECT 
    a.actor_name AS EDITOR_NAME,
    COUNT(r.rev_id) AS TOTAL_EDITS,
    ROUND(((COUNT(r.rev_id) - @Average_edits) / @Average_edits) * 100) AS PERCENTAGE
FROM 
    revision AS r
JOIN 
    actor AS a ON r.rev_actor = a.actor_id
WHERE 
    r.rev_timestamp BETWEEN DATE_FORMAT(CURDATE() - INTERVAL 2 MONTH, '%Y-%m-01') 
                        AND LAST_DAY(CURDATE()) 
GROUP BY 
    EDITOR_NAME
ORDER BY 
    Total_edits DESC
LIMIT 5;

SQL

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