已知 $f\left(x\right)=\frac{x}{1+x},x\ge 0$，若 $f_1\left(x\right)=f\left(x\right),f_{n+1}\left(x\right)=f\left(f_n\right(x\left)\right),n\in N_{+}$，则 $f_{2014}\left(x\right)$的表达式为.