"NumberOfPlayers" or other variables to count players in a party?

I want to increase a boss’s skills and/or stats based on the amount of players in your multiplayer party. To test this, I started editing a passive skill called “damage_totaladjuster”, which is used by many enemies in the game, and most (if not all) bosses. Its skill level is calculated using “charLevel”, which I assume is the boss’s character level. So I did a bunch of searches in the DBR files to find an equation variable that would be able to accomplish what I want.

I found 2 that looked promising: “numberOfPlayers” which is used primarily to calculate loot tables, and “evaluatingPartyMemberCount” which is used to calculate shared experience. (Also, “averagePlayerLevel” was often used in those same equations, but that one wouldn’t accomplish what I need.)

Both of these options seemed like they should probably return a number based upon how many players are in the party, but they don’t work like that for some reason. I tried to have damage_totaladjuster increase its level using the equation: “1+(numberOfPlayers)”, but the skill always stays at level 1. I tried some other variations, such as “1+(numberOfPlayers*2)”, “numberOfPlayers+1”, etc, but the skill always stays at level 1, suggesting that “numberOfPlayers” is always returning a zero. This happens both in single player and in multiplayer with 2 people. I did similar tests with evaluatingPartyMemberCount with the same results. I did do a control test first: simply putting a “2” in the equation field did set the skill level at 2, as it should.

Does anyone know what might be happening here? Am I doing something wrong, or do those variables simply not work in those situations? Is there a different variable that I could use instead? Any help is appreciated.