Think you can use this Excel function to calculate a precise live age...I have added this but I want to be very transparent about how I worked it out so that it doesn't cause any issues if someone wants to use that data for something important, they can check my numbers etc.
It is calculated by the total days between the date of birth and the current date listed in the bottom left of the spreadsheet, the total days divided by the number of players for average days then divided by 365.25 for leap years.
=YEARFRAC(BD, TODAY(), 1)
Replacing BD with the cell containing their birthday.