$\int _{-1}^{1}\:f\left ( x \right )dx$ calculated using trapezoidal rule for the values given in the table is ______ (rounded off to $2$ decimal places).

$$\begin{array}{|cl|cI|cI|cI|cI|cI|}\hline

&\text{x} & \text{-1} & \text{-2/3} & \text{-1/3} & \text{0} & \text{1/3} & \text{2/3} & \text{1} \\ \hline &\text{f(x)} & \text{0.37} & \text{0.51} & \text{0.71} & \text{1.0} & \text{1.40} & \text{1.95} & \text{2.71} \\ \hline \end{array}$$