5 Registrar gTld: Top Registrars, TLD Marketshare, Top Registrars by Country - DomainState.com
Registrar Stats

One.com A/S

http://oneregistry.co/

One.com A/S Domain Extensions
TLD MARKET SHARE TOTAL GENERAL AVAILABILITY
.icu 86.06% 1,077,733 Available for registration
.one 13.94% 174,504 Available for registration