400-450 would be people who have Masters, aged between 27-29 and ielts score of above 7+,
Statistics shows world population between 27-29 is 593,945,015. If 0.01% are in the pool ( i would say even less), that number is 59394. If 3.5% of these people meet the above criteria, then the number is 2078. Looking at CIC trend, ITA have increased roughly by 400 on every draw. So, cut off is very likely to be on lower 400's tommorow this time.