Not Pascal's Identity

Algebra Level 2

$\frac {C_1}{C_0} + 2\ \frac {C_2}{C_1} + 3\ \frac {C_3}{C_2} + \ldots + 15\ \frac {C_{15}}{C_{14}}$

Let $C_r$ denote the binomial coefficient ${ 15 \choose r }$ . What is the value of the expression above?