Breast feeding/pumping moms

I feel like i have seen a lot of posts lately about pumping output and some of the oz are a lot. I nurse my baby on demand on weekends, but during the week I work, so i only nurse him at 5am and 7pm. I pump 3 times at work, at 9, 12, and 3pm (this is usually when he nurses on weekends as well) Recently i have noticed that im only getting 2-2.5 oz each time i pump (my let downs seem to have less milk, like 1/2 the amount they use to have) , so im only making 6oz all day so im sure hes only getting maybe 12oz of milk a day. He eats 3 meals a day and 2 snacks, and hes growing well, im just curious, i see comments that baby is still drinking 24-30 oz a day, i was wondering if there are any babies out there like my son who are only drinking maybe 12-14 a day!