Yes I always took 'a centred average' to mean that. The mid-point of the data being averaged, so for a 13 month period it will give an average of all the data from the 6.5 months previous and the 6.5 months afterwards.
Hence why the 'rolling 7days average' that gets reported on the 'rona figures always seems to show a number that appears higher when the daily rates are dropping - this is because it averages only the previous 7 days and none of the following days as they haven't yet occurred.
Hence why the 'rolling 7days average' that gets reported on the 'rona figures always seems to show a number that appears higher when the daily rates are dropping - this is because it averages only the previous 7 days and none of the following days as they haven't yet occurred.