for loops problem

[error0024]

Loops
    Events
        Time - Every 120.00 seconds of game time
    Conditions
    Actions
        For each (Integer A) from 1 to 50, do (Actions)
            Loop - Actions
                Unit - Create 1 Footman for Player 12 (Brown) at (Center of (Playable map area)) facing (Position of (Triggering unit))
                Set Check_Monster_Amount[1] = (Check_Monster_Amount[1] + 1)
                Wait 0.20 seconds
        Wait 10.00 seconds
        Game - Display to Player Group - Player 1 (Red) for 10.00 seconds the text: (String(Check_Monster_Amount[1]))

hello i created this trigger for my tower defense map i used monster check amount each waves its different amount .... why
anyone have any idea its not exact example like 50 spawns
but it creates 48 or 49 or 51 or 55

 

[what666said]

Is there another trigger that might be changing the "Integer A" value (it's a global variable for all triggers), between one of the waits?