There is no standard guideline on how much yield is considered normal. Some mothers yield more and some yield lesser. It can be due to hormonal issues and demand of baby's intake. The more discipline you pump and latch, the more milk you can produce. You can also take milk booster food like oats, chocolate, papaya fish soups, carrots, nuts and durians to increase mill supply. Do not be too stress about milk supply, if insufficent, supplement with formula milk.
Every mother's milk capacity is different so there's no "normal" yield. And don't compare your pump output with others. As long as you are producing enough to meet your LO's demands, that's all that matters. Diaper count of 5-6 wet/dirty diapers in 24h would indicate that your baby is having enough.