Why pmval shows every seconds information, even though pmlogger logging interval is 60 seconds?

Issue

• pmval shows every seconds data from pmlogger archive, is this correct? pmlogger collect data every seconds?

• pmval shows every seconds data from pmlogger archive, it seems different from pmlogger's default interval 60 seconds.

  $  pmval kernel.all.cpu.sys  -a /var/log/pcp/pmlogger/hostname/20230607.00.10.0
  [...]
  00:11:16.623               0.1620   <<=== Each seconds have different value
  00:11:17.623               0.1190   
  00:11:18.623               0.1130   
  [...]
  $ grep PMLOGGER_INTERVAL /etc/sysconfig/pmlogger /usr/share/pcp/zeroconf/pmlogger
  /etc/sysconfig/pmlogger:# PMLOGGER_INTERVAL=60