Note that the availability of emoji domains is limited. As of August 2017, there were eight top-level domains for which registration of emoji domain names was possible, all of which are ccTLDs: .cf, .fm, .ga, .gq, .ml, .tk, .to, and .ws.

https://en.wikipedia.org/wiki/Emoji_domain

Meanwhile, the total number of TLDs was 1543 TLDs as of April 2018. As of May 2017, there were 255 Country code top-level domains.

https://en.wikipedia.org/wiki/List_of_Internet_top-level_dom...

8 / 1543 ~= 0.5% of all TLDs support emoji.

8 / 255 ~= 3% of all ccTLDs.