We were designing a feature for a system, in which a postcode search would return not the addresses within one postcode, but a list of individuals registered at that postcode.

In order for the UX design to be right, we needed to understand the average number of returns, but also the maximum.

The design, requirements team and system architects met to discuss this feature, and although no-one could answer it with data, there was anecdotal evidence to indicate that really large numbers could exist.

Do you have any examples, possibly from system design experience, where you've come across very large numbers of individuals or addresses associated with a postcode?

We were designing a feature for a system, in which a postcode search would return not the addresses within one postcode, but a list of individuals registered at that postcode.

In order for the UX design to be right, we needed to understand the average number of returns, but also the maximum.

The design, requirements team and system architects met to discuss this feature, and although no-one could answer it with data, there was anecdotal evidence to indicate that really large numbers could exist.

Do you have any examples, possibly from system design experience, where you've come across very large numbers of individuals or addresses associated with a postcode?

The question IS unanswerable, as I don't have the ability to get the postal service to do a query. That's why I'm asking for anecdotal evidence.

The UX question is about interface design. Knowing what your minimum, maximum and average results are is essential to create the right design. The reason I'm asking is that it's a question that comes up again and again in my system design so maybe others will have had the same.