All of the things in parentheses are of the form $\frac{1}{n}+\frac{2}{n}+\frac{3}{n}+\cdots+\frac{n-2}{n}+\frac{n-1}{n}$. If we add the fractions together, we get $\frac{\frac{n(n-1)}{2}}{n} = \frac{n-1}{2}$. Now we can rewrite each of the things in parantheses to get $\frac{1}{2}+\frac{2}{2}+\frac{3}{2}+\cdots+\frac{999}{2}$. Adding the fractions together gives $\frac{\frac{999\cdot1000}{2}}{2} = 999\cdot250 = \boxed{249750}$