Doing more than required

I was wondering if someone can give me some advice on what step to take next. Should I tell someone or just continue to do the normal level of work?

We are required to do a certain amount each month but I'm finding myself bored a lot. Due to this, I don't stop at the minimums our boss puts in place. During the last few months, I did 2-4 times the amount of work that is required and I wasn't the only person with this much stuff done.

Every time our results come out, I get abuse from a couple of different members of my team about this, asking me to slow down so they won't raise the requirement and telling me to stop being a spoilsport as the current target has a lot of free time to do things. One of the girls, who is friends with someone who did the same work as me, was cursing me out of it outside of work last week and then told her friend that her amount of work was fine.

My boss is happy with my work but if I said anything against them, it would be clear it was me complaining and this will just make the whole thing worse.

I'm now just doing the minimum amount to stop being bombarded with this abuse. But I don't know how to act to these people? I just ignored them during the last few times but I'm sick of it.