Never think about it that way. If you think your novel's ready to be published, you'd better feel totally confident that it's better than 99% of submissions.
Let's break it down:
90%- literally unpublishable. These aren't just boring stories written with a lot of adverbs, these are manuscripts that may not even be written entirely in letters recognizable to humans.
5%- while still better than 90% of the other submissions, these manuscripts aren't great. Sure, they tell a story, but it's a boring story, or it's a great story that's been told to death.
4%- These manuscripts are fine. Compelling, well-written, but they're not what the agent's looking for.
1%- This is where your MS should be before you query. Well-written, compelling, and *for the agent you're querying.*
That means don't shop your SF/F saga to an agent who doesn't rep SF/F, or maybe she does, but has only sold a tiny fraction of those books. That means research agents: for me, I'm putting agents who are passionate about insider stories with strong voice and dark humor way above the agents who like more lyrical literary family sagas.
100% of 90% of submitted queries will never be represented or sold, so don't worry about those guys. Either you're in that 90%, or you're not. If you're not, focus on beating out the remaining 9%. If an agent gets 100 queries a week, 90 of them will be auto-rejects. Just make your query, your story, better than 9 other ones. It's that easy.
(So sayeth the woman who is baking her story until it's ready to go, and is researching agents until she finds the exact right top ones.)