audit syslog doesn't show sql_text for non sysdba users

database  10.2.0.2   configurations             and            OS redhat 5   configurations          /etc/syslog.conf    " user.notice        /var/log/syslog  "
audit_sys_operations= TRUE                                                     
audit_syslog_level    = USER                                                      
audit_trail                = OS 

AUDIT ALL BY system BY ACCESS; AUDIT SELECT TABLE, UPDATE TABLE, INSERT TABLE, DELETE TABLE BY system BY ACCESS; AUDIT select any table by system BY ACCESS;this is  syslog sample    for  sysdba  and  system  user

conn   / as sysdba
select * from scott.dept;

syslog file   show :

Jan 21 10:51:41 ruhs1dbs01 Oracle Audit[27187]: ACTION : 'select * from  scott.dept' DATABASE USER: '/' PRIVILEGE : SYSDBA CLIENT USER: oracle CLIENT TERMINAL: pts/4 STATUS: 0

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conn  system/******* 

select * from  scott.emp;