This is hard to say because the ranks are decided relatively. You might score less but if others score less than you then your rank will still be under 1000.

But according to past statistics, I think you should try to score around 170 to be somewhat sure that you'll get a rank under 1000.

But again, it's all relative. If you score 170 and a thousand people score more than 170, you'll not get a rank under 1000.