DB CPU event in top 5 of AWR report question

Question

The top 5 foreground event in my AWR report is as follows. I am trying to understand if my db(system) is CPU bound.The elapsed time is 30 minutes and DB time is 675 in the load profile section. There are 32 cpus. The available CPU is 30*60*32 => 57600. The  DB CPU below is 35227. This is about 61 %. At what percentage of DB CPU do I consider my system is CPU bound ?. Also I want to make sure the method I arrived at this is correct or not. Please help. Event           Waits Time(s) Avg wait (ms) % DB time     Wait Class DB CPU                 35,277 87.12 DBMS_LDAP: LDAP operation 3,683       10,061       366         9.1             Other db file sequential read 233,584         933       4         2.3               User I/O read by other session 41,686           190       5       0.47                 User I/O log file sync 70,932      166       2       0.41                           Commit

Answer 1

Why does the top 5 foreground indicate 87 % below the  % DB Time  column ? While my calculation shows 61 %, Which is correct for the interpretation if the system is CPU bound. The 2 lines of top 5 events are as follows
Event
Waits
Time(s)
Avg wait (ms)
% DB time
Wait Class
DB CPU
35,277
87.12