For any real number $x$, let $\lfloor x \rfloor$ denote the largest integer less than or equal to $x$. If $$I = \int_0^{10} \left\lfloor \frac{10x}{x+1} \right\rfloor dx,$$ then the value of $9I$ is ____.
For any real number $x$, let $\lfloor x \rfloor$ denote the largest integer less than or equal to $x$. If
$$I = \int_0^{10} \left\lfloor \frac{10x}{x+1} \right\rfloor dx,$$
then the value of $9I$ is ____.