It is per year indeed, and yes, asteroid mining is really underwhelming considering the costs to set it up. You are probably better of making some "mining modules" which you tow to a place, because those will never need any upgrades later on then, and are essentially manufactured orbital mines.
Towing is then done with otherwise useful specialized tow designs, or tankers, and once the mining side fills you just come around with a casual freighter fleet to get the spoils like everywhere else. (...or to deliver mass drivers if possible)
I have done complete mining ships like yours very often nonetheless, but just know that those are more for flavor and fantasy rather than efficient play styles.
Other notes to the design:
- still classed "fuel harvester"
- too much cargo even for a mobile miner design (needs about 200 years to fill even on a all-resource, all-avail.-1 asteroid. ..which don't exist
)
- even civil ships should have enough MSP to do the maximum component repair once. This is important, because otherwise you will be incapable of repairing such ship outside of gigantic hangars bays should it ever somehow receive damage.(e.g.: rescuing survivors)