MaxMind DB中accuracy_radius字段的单位是什么?

What are the units of the accuracy_radius field in MaxMind DB?

此字段于 2016 年 4 月添加到数据库中,但发行说明未说明单位是什么。

http://dev.maxmind.com/geoip/geoip2/geolite2/

https://dev.maxmind.com/geoip/geoip2/release-notes/

The radius in kilometers around the specified location where the IP address is likely to be.

http://dev.maxmind.com/geoip/geoip2/web-services/