Perhaps this isn't really specifically a GIS question, but I've been using ArcMap to measure distances from the access points of green spaces in Bristol to postcode centroids and would like to use these distances to calculate the percentage of the population of each ward and of the city as a whole, living certain distances away from the spaces. I'm not sure the best way to go about calculating these statistics though as I can't find population data at a postcode level for the number of individuals living within each postcode.
As I've managed to find population counts for each administrative ward (Release Edition Reference Tables - ONS) and the number of domestic delivery points at each postcode centroid was included in the excel spreadsheet I downloaded to obtain the postcode data, I was thinking perhaps I could divide the total population of each ward by the number of domestic delivery points within it to work out the average number of individuals living at each delivery point. I could then multiply this by the number of domestic delivery points for each postcode centroid to calculate the number of individuals living at each one. This could then obviously be used to work out the percentage of the population of each ward living at each postcode.
I'm not sure whether this would be a sensible way of going about this though, and whether it would make sense to relate the ward level statistics to those at a postcode level, so any advice would be really appreciated. Thanks.