Hi Maggie
Get onto your Family assistance office they will send you out the exact % that you are entitled too and your day care centre have whats called a centre provider number that you give to Family assistance office and they communicate and give you the correct rebate as per your annual income estimate
Ours is about 60k and while I am not at work we will get 56% child care rebate and we get $106 per fortnight, we are married and stuff and that is all declared... but when I go back to work.. which is full time at 37k per year on top of DH self employed earnings... our rebate goes to 16% and no family assistance fortnightly payment.

Its a GREAT help while I am not working and even though its only a little % of CC rebate when I do go back its still better than a kick up the bum I suppose

So yeah give family assistance a call and they will answer all of your questions.. I found them pretty helpful and prompt with thier service and information

Good luck
xox