Below is a comment of mine in this forum:
I know "the proportion of" works in both cases, but I'm not sure if "the rate of" does. And what if I rephrase the first sentence into the second one, does the answer change?
Sometimes when I ask questions here, I feel tempted to link my two sentences with "and". I know other phrases like besides, furthermore, moreover, on top of that,..., but I feel like they are somewhat too formal for situations like this, that is asking people on a forum. I mean when I ask questions here, even though it's written discourse, it seems like we're chatting casually to me. But I know we don't start a sentence with "And" or "But", so what would you suggest I should use in this situation?