SELECT IdShooter,gruppe,GroupSumFullValue
FROM (
SELECT TOP 2 IdShooter,
ShotCount / 10 * 10 AS gruppe,
sum(FullValue) AS GroupSumFullValue
FROM tabelle
GROUP BY IdShooter,ShotCount / 10 * 10
ORDER BY IdShooter,ShotCount / 10 * 10 DESC
) t1
UNION ALL
SELECT IdShooter,NULL,sum(GroupSumFullValue)
FROM (
SELECT TOP 2 IdShooter,
ShotCount / 10 * 10 AS gruppe,
sum(FullValue) AS GroupSumFullValue
FROM tabelle
GROUP BY IdShooter,ShotCount / 10 * 10
ORDER BY IdShooter,ShotCount / 10 * 10 DESC
) t2
GROUP BY IdShooter