Increasing amount of milk as older?

My baby just turned 10 months old. Are we supposed to be increasing the amount of milk they are having? I pump while at work and breastfeed while at home. While I'm at work he typically has between 16oz (8:30-5pm) between 4 bottles. Should I have upped the amount in his bottle at some point? He's still waking up at least 3-4 times during the night for substantial feeds and I was wondering today if it's cause he needs more during the day? He's been eating 3 meals a day at this point and at least for the last 3 weeks has actually been eating a substantial amount. I guess I had always read for breastfeeding you typically don't increase their volume, but did you guys find this was true? It does seem weird and now my pumping output is about 25% less than it was about 2 months ago so some days I'm only getting around 12oz at work. Any advice or should I try increasing his bottle for a few days and see what happens or is it not necessary at this point?