The state variable representation of a system is given by

\(\dot x = \left[ {\begin{array}{*{20}{c}} { - 4}&{ - 1}\\ 0&{ - 3} \end{array}} \right]x + \left[ {\begin{array}{*{20}{c}} 1\\ 1 \end{array}} \right]u\left( t \right)\)

\(y\left( t \right) = \left[ {\begin{array}{*{20}{c}} 1&0 \end{array}} \right]x\left( t \right)\)

The damping ratio of the system is ______