The increase in calculated entropy comes from the first iteration being slower than the rest, but that's a bit misleading, because the first call is always going to be slower.
Can you run the program 10 times and show me how much variance there actually is in the first column? Because if all the values lie between (say) 756000 and 757000 that's actually just 10 bits of entropy, not 19.5, and if the same applies to the other values, you're much closer to the original 90 bits.
Can you run the program 10 times and show me how much variance there actually is in the first column? Because if all the values lie between (say) 756000 and 757000 that's actually just 10 bits of entropy, not 19.5, and if the same applies to the other values, you're much closer to the original 90 bits.