Every level increases the salary with a %. Like crazy said the formula looks like 1,18^PA and that means one lvl of passing for a guard increases salary by 18%. So the higher lvl of passing the more salary the guy have and 18% of a large number is more then 18% of a small number.
                                
                                
                                
                                
                                
                                
                                    
                                       
                                        
                                    /Mannen