The best two to answer this that I know of atm are #[2] and #[3]
Discussion
Thanks for bringing this up, here is a chart that's long overdue. Events/pubkeys per relay in the last 7 days.
https://stats.nostr.band/#relay_writers
I can't measure their read-load obviously, but can tell how much events are written. As I expected, the list of top relays by number of events is materially different from list of top relays by contact list. Does this tell you anything new/interesting?
Whoa, I had not seen these stats, they are amazing.
I built them this morning after seeing this thread