Agree that your latency is already low, but if you want more then perhaps check the firewire cards buffer setting. The asymmetric latency your showing is symptomatic of the firewire card output buffer. It’s quite probably correct, but it is also adjustable, at least it is on my firewire card when I was using it.
From memory, as I no longer use firewire, the yamaha firewire asio driver had a utility where it was installed which you could run to change it.