Actually now that I think about it, you'll probably have to aim slightly higher than that. You'll want to keep at least that average, but also earn enough to pass the users below the top 10 who might move up and be past those points in 4 months' time: platypus_hex, ekult, clinkster, BobParker, tetsuoswrath and rpc1 are pretty active on the site at the moment. It's hard to know exactly what rate you'll need to be at to be #10 or higher in 4 months' time.
It would be great to see you achieve that goal though! All the best with it.