An insurance company sells automobile liability and collision insurance. Let X denote the percentage of liability policies that will be renewed at the end of their terms and Y the percentage of collision policies that will be renewed at the end of their terms. X and Y have the joint cumulative distribution function F(x, y) = \dfrac{xy(x+y)}{2{,}000{,}000}, 0\le x\le 100, 0\le y \le 100. Calculate Var(X).