Push down GUI everytime for loop cycles through Array

Im trying to display a GUI box every time i cycle through a for function. And every time it does add a little bit to the height variable for that gui box so it goes under the previous one. Here is what i have:

     for (i = 0; i < indivSpotNo.Length; i++) {
         hgt += 30f;
         GUI.Box (new Rect (20, hgt, 30, 25), indivSpotNo [i].ToString());
     }
 }

except what is happening is the hgt variable isnt stopping for each one its just adding every time and pushing them all off screen. What else can i do that will achieve this?