CONO-SUR 2020 Problem 6

A $4$ x $4$ square board is called $brasuca$ if it follows all the conditions:

• each box contains one of the numbers $0, 1, 2, 3, 4$ or $5$ ; • the sum of the numbers in each line is $5$ ; • the sum of the numbers in each column is $5$ ; • the sum of the numbers on each diagonal of four squares is $5$ ; • the number written in the upper left box of the board is less than or equal to the other numbers the board; • when dividing the board into four $2$ × $2$ squares, in each of them the sum of the four numbers is $5$ .

How many $"brasucas"$ boards are there?