A rectangular cross-section of a reinforced concrete beam is shown in the figure. The diameter of each reinforcing bar is $\text{16 mm}$. The values of modulus of elasticity of concrete and steel are $2.0 \times 10^{4} \text{ MPa}$ and $2.1 \times 10^{5} \text{ MPa}$, respectively.
The distance of the centroidal axis from the centerline of the reinforcement $\text{(x)}$ for the uncracked section (in $\text{mm}, \textit{round off to one decimal place}$) is ______________