How to find number of sessions per hour for EACH INSTANCE in a RAC

SELECT
to_char(TRUNC(s.begin_interval_time,'HH24'),'DD-MON-YYYY HH24:MI:SS') snap_begin,
r.instance_number instance,
r.current_utilization sessions
FROM
dba_hist_resource_limit r,
dba_hist_snapshot s
WHERE ( TRUNC(s.begin_interval_time,'HH24'),s.snap_id ) IN
(
--Select the Maximum of the Snapshot IDs within an hour if all of the snapshot IDs
--have the same number of sessions
SELECT TRUNC(sn.begin_interval_time,'HH24'),MAX(rl.snap_id)
FROM dba_hist_resource_limit rl,dba_hist_snapshot sn
WHERE TRUNC(sn.begin_interval_time) >= TRUNC(sysdate-1)
AND rl.snap_id = sn.snap_id
AND rl.resource_name = 'sessions'
AND rl.instance_number = sn.instance_number
AND ( TRUNC(sn.begin_interval_time,'HH24'),rl.CURRENT_UTILIZATION ) IN
(
--Select the Maximum no.of sessions for a given begin interval time
SELECT TRUNC(s.begin_interval_time,'HH24'),MAX(r.CURRENT_UTILIZATION) "no_of_sess"
FROM dba_hist_resource_limit r,dba_hist_snapshot s
WHERE r.snap_id = s.snap_id
AND TRUNC(s.begin_interval_time) >= TRUNC(sysdate-1)
AND r.instance_number=s.instance_number
AND r.resource_name = 'sessions'
GROUP BY TRUNC(s.begin_interval_time,'HH24')
)
GROUP BY TRUNC(sn.begin_interval_time,'HH24'),CURRENT_UTILIZATION
)
AND r.snap_id = s.snap_id
AND r.instance_number = s.instance_number
AND r.resource_name = 'sessions'
ORDER BY snap_begin,instance