Nice work. Just one thing, analyze sites by total referring domains is not accurate as your result showed. A backlink can be easily faked and you can literally

Nice work. Just one thing, analyze sites by total referring domains is not accurate as your result showed. A backlink can be easily faked and you can literally spam 1 million links within 1 day for any domain. Thus, this data source is not much useful. For a more accurate result, try to use Ahrefs top 1 million domains, ranked by their traffics. Ahrefs rank sites by their ranking keywords, thus infer the traffic numbers, meaning, these websites are live, and ranking with some keywords. You will see the result is much more accurate then, maybe not even a single website will be offline, because they are earning good cash.