Level 29

You see a room which is 10x10m wide (0x0 to 9x9).
Every square has the exact temperature of 4°C. We apply continuously 191°C heat to the field 6x8
What is the temperature (rounded to whole numbers) in the field 9x6 after 74 iterations according to the Gauss-Seidel iteration

Field in the beginning

4444444444
4444444444
4444444444
4444444444
4444444444
4444444444
4444444444
4444444444
4444444444
4444444444

Field after 4 iterations (rounded after 4th iteration)

1111111110
1222222221
1233333321
1233333321
1233444432
123347111074
12338223830188
12362259110693615
12310361072961164919
01272357102613012

Temperature in field 9x6 after 74 iterations: