If you can't care about your community enough to donate something, then I think your values may need reexamining. Even if that something is donation of old clothes and used items instead of throwing everything away.
And finally, it's not about how many people donate and how many don't. It's the right thing to do, and asking if you're "the norm" is just looking for a justification. Do the right thing. Don't just be narrowly selfish.