SELECT ServerName ,
        AVG(CASE WHEN `Time` >= (UNIX_TIMESTAMP(DATE_ADD(NOW(), INTERVAL -4 WEEK))*1000)
                        AND `Time` <= (UNIX_TIMESTAMP(DATE_ADD(NOW(), INTERVAL -3 WEEK))*1000)
             THEN PlayerCount
             ELSE NULL
        END) AS `4 weeks ago`,
        AVG(CASE WHEN `Time` >= (UNIX_TIMESTAMP(DATE_ADD(NOW(), INTERVAL -3 WEEK))*1000)
                        AND `Time` <= (UNIX_TIMESTAMP(DATE_ADD(NOW(), INTERVAL -2 WEEK))*1000)
             THEN PlayerCount
             ELSE NULL
        END) AS `3 weeks ago`,
        AVG(CASE WHEN `Time` >= (UNIX_TIMESTAMP(DATE_ADD(NOW(), INTERVAL -2 WEEK))*1000)
                        AND `Time` <= (UNIX_TIMESTAMP(DATE_ADD(NOW(), INTERVAL -1 WEEK))*1000)
             THEN PlayerCount
             ELSE NULL
        END) AS `last week`,
        AVG(CASE WHEN `Time` >= (UNIX_TIMESTAMP(DATE_ADD(NOW(), INTERVAL -1 WEEK))*1000)
             THEN PlayerCount
             ELSE NULL
        END) AS `this week`

        FROM `ServerStats`
        WHERE `Time` >= (UNIX_TIMESTAMP(DATE_ADD(NOW(), INTERVAL -4 WEEK))*1000)
        GROUP BY `ServerName`
ORDER BY `this week`  DESC

WEEKDAY(FROM_UNIXTIME(`Time`/1000)) FROM `ServerStats`