The average rate at which energy is conducted outward through the ground surface in a certain region is 30.2 mW/m2, and the average thermal conductivity of the near-surface rocks is 4.00 W/m·K. Assuming a surface temperature of 11.4°C, find the temperature (in Celsius) at a depth of 35.0 km (near the base of the crust). Ignore the heat generated by the presence of radioactive elements.