"Sean is correct, if we still have people living then you can't calculate what the mean survival time is because it's getting better everyday."


I hated all math, especially statistics, in my 16 years of formal education, but it seems to me you could come up with "a number to date and still calculating" and compare with SOC even if they are also "a number to date and still calculating" and have a reasonable comparison. Seems like waiting for all living sujects to die of old age before calculating would be stupid and missing out on useful information. I would like to see the comparison.