Whether they do this by multiplying the increase by 12 or raising the ratio to the twelfth power, I am not sure.
Most likely using it to scale a model that includes seasonal fluctuation. Ex: If 5% of a year's inflows are typically in March, then 5k people in March would be an inflow 100k, annualized. Probably an attempt to have the bars compare changes due to policy and not weather/holidays.
Most likely using it to scale a model that includes seasonal fluctuation. Ex: If 5% of a year's inflows are typically in March, then 5k people in March would be an inflow 100k, annualized. Probably an attempt to have the bars compare changes due to policy and not weather/holidays.