Which schema is the right place to report host boot time

Hello,

We would like to export the host boot time duration through the BMC's Redfish interface.
And we want some suggestions for where is the right place to do that.

We found that `ComputerSystem/BootProgress/LastState` is close to our requirements. however this schema only records the timestamp instead of the duration. Also the classification of the `state` is quite different from ours.

Currently we follow the boot stage classification from `systemd`, which divided boot state into 5 stages:

1. firmware
   
2. loader
3. kernel
4. initRD
   
5. userspace

So we would like to know where is the right place to report the boot time duration with a customized classification?

Thanks!