My Calculator don't have enough Input Power!

Algebra Level 5

Let $f(x) = \frac {x^3}{1-3x+3x^2}$

If the value of the expression below can be written in the form of $\frac {a}{b}$ for coprime positive integers $a,b$ , what is the value of $a+b$ ?

$f \left ( \frac {1}{2014} \right ) + f \left ( \frac {2}{2014} \right ) + \ldots + f \left ( \frac {2013}{2014} \right )$