Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 19°C. We apply continuously 161°C heat to the field 9x3
What is the temperature (rounded to whole numbers) in the field 5x4 after 73 iterations according to the Gauss-Seidel iteration

Field in the beginning

19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919
19191919191919191919

Field after 4 iterations (rounded after 4th iteration)

3456666677
48911111111142124
591213141417275173
61113151617224191221
6111416171823365877
6111416171821273432
6111416171819212116
610131415161616149
4710111212121195
2456666642

Temperature in field 5x4 after 73 iterations: