Oracle Performance Tuning Script - Top Wait Events Since Instance Startup

Oracle Performance Tuning Script - Top Wait Events Since Instance Startup col event format a60 select event, total_waits, time_waited from v$system_event e, v$event_name n where n.event_id = e.event_id and n.wait_class !='Idle' and n.wait_class = (select wait_class from v$session_wait_class where wait_class !='Idle' group by wait_class having sum(time_waited) = (select max(sum(time_waited)) from v$session_wait_class where wait_class !='Idle' group by (wait_class))) order by 3;