The resistance spot welding of two $\text{1.55 mm}$ thick metal sheets is performed using welding current of $\text{10000 A}$ for $\text{0.25 s}$. The contact resistance at the interface of the metal sheets is $0.0001\; \Omega$ . The volume of weld nugget formed after welding is $70 \text{ mm}^{3}$. Considering the heat required to melt unit volume of metal is $12 \text{ J/mm}^{3}$, the thermal efficiency of the welding process is _______ $\%$ ($\textit{round off to one decimal place}$).