Where to find firewall rule stats from terminal

Hi All

I have an EdgeRouter Lite-3 which I've setup with a zone based firewall, a couple of VLAN's and an inbound and outbound VPN.  This means that I have quite a few firewall rules.

I'd like to review the rules to see which ones are being used and which ones aren't (so that I can remove the not used rules). I can do this through the GUI by clicking on the ruleset and then going to stats.  However I'd like to do this all at once without having to go through each ruleset in turn.

The stats (number of packets and number of bytes) must exist somewhere on the EdgeRouter (as they are saved) but I can't find where.  Does anyone know where they are kept?

I've tried:

1. /var/log (this contains the rules that I have logging enabled for)
2. Looking through files recently modified on the EdgeRouter
3. Using Fiddler to look at the traffic generated by the GUI (all settings and data is downloaded in JSON, however the stats are provided by a websocket and I don't know how to reverse this)

Any suggestions would be appreciated.

Thanks

Nick