49. Solving a chemistry problem

Silver iodide sol is obtained by mixing equal volumes of solutions of potassium iodide and silver nitrate. The coagulation thresholds for various electrolytes and a given sol have the following values (mmol/l):
CCa(NO3)2 = 315;
CNaCl= 300;
CMgCl2 = 320;
CNa3PO4 = 0.6;
CNa2SO4 = 20;
СAlCl3 = 330.
Which of the electrolytes: KI or AgNO3 is taken in a higher concentration for the preparation of the sol? Give a reasoned answer.