If one parent has primary placement of the minor children in a divorce how is child support amount set?

The Wisconsin Administrative Code, Chapter DCF 150, sets forth the standard percentage of gross income due from the non-primary parent as and for child support. The percentages are as follows:

(a) 17% for one child;

(b) 25% for 2 children;

(c) 29% for 3 children;

(d) 31% for 4 children; and

(e) 34% for 5 or more children.

The amount of child support may vary due to the payers level of income.

If one parent has primary placement of the minor children in a divorce how is child support amount set?