104 names hold more of the register than the 8,205 rarest combined

This site counts real registrations — licences and shelter intakes published as open data — and it counts a lot of them. Spread across the catalogue they would give every name a few dozen. They are not spread. Half of every registration sits on a few hundred names, and the lower half of the catalogue, six thousand names, divides about a sixteenth of the register between them.

The four bands are not four quarters

The catalogue sorts names into popular, common, rare and very unique. The band names describe how crowded a name is, and it is easy to read them as slices of similar size. They are nothing like it: 104 names are popular, 399 common, 3,487 rare and 8,205 very unique.

Weigh them by registrations rather than by names and the order turns over. The 104 popular names hold 160,590 registrations between them. The 8,205 very-unique ones — nearly eighty times as many names — hold 147,159. Less. A hundred names outweigh eight thousand.

The largest share belongs to neither end. The rare band holds 318,544 registrations across 3,487 names, more than any other band, because it is where a catalogue this size keeps most of its usable middle.

What the average hides

Averages per band tell the story cleanly enough — 1,544 registrations for a popular name, 566 for a common one, 91 for a rare one, 18 for a very-unique one. Across the whole catalogue the average is about seventy. The median is sixteen.

A mean four times its median is the signature of a distribution with a long tail, and it is why the average is the wrong number to plan with. Almost no name gets seventy registrations. Most get a handful; a few hundred get thousands.

Why the site does not rank on this

It would be simpler to order every list by raw registrations, and this site deliberately does not. A raw total ranks a name common in a large city above one common in a small one purely because the large city published a bigger file, so popularity here is a share measured per source group instead. The concentration on this page is a fact about the registers, not about the ranking — it is what the ranking was built to correct for.

Both things are true at once. The registers are steeply concentrated, and the ordering you see refuses to inherit that steepness from whichever city happened to publish most.

What it means for choosing

If you want a name nobody else is calling across the park, the tail is enormous and cheap to reach: 8,205 names sit in the very-unique band at 18 registrations each. If you want a name people recognise without it being the third one at the vet, the rare and common bands between them hold most of the register and most of the catalogue.

And if a name you like turns out to be popular, that is 104 names out of more than twelve thousand. Being in that group is unusual in itself.