Credit Score Question?

Recently got my credit report cleaned up to the tune of a 705 score back in December/Jan. This score literally hasn't moved a point since then. Haven't missed a payment on anything, haven't racked up tons of debt, haven't made any big purchases. I've been very credit conscious being that I'd like to buy a condo early next year and not get fleeced with a percentage rate. It's been almost 6 months. Why wouldn't it move at all...I thought time helps raise your score?? It almost doesn't seem fair that a score can go down so easily yet raising it 20 points is like trying to get water from a rock...