Oh, this is explained several times.
You have 18 quotas.
In an equation calculate the "number" (1-18)
and set the quota for each outcome.

Equation could be (numerical codes , 1, 2, 3,...)
{6 * (city - 1) + panel}

Joffm

I just give you some template if more that 50 combination then manually set limit for each number its too time consume
Any other we can do easily to avoid to do set limit one by one

Hi,
time consuming?
I do not think so. I should say that it is done in less than an hour.

But there might be an option.
This is a rough idea, that came to my mind. Not tested.
Use the shown equation (adapted to your real scenario). Let's say fom 1-52.
In a following equation count how many times the actual combination already occured - with function "statCountIf()".
Like {if(statCountIf(eqationCode.sgqa,calculatedNumber) ge maxNumberOfCombination,0,1)}

Then you have only one quota on this new equation (screenout, if 0)

Joffm