What percent of birds are flightless?

There are about 11,032 known species of birds including 18 species of penguins, 4 of emus & cassowaries, 2 rheas, 1 ostriich and 3 kiwis. As far as I know, apart from these 28 species, almost all others are capable of flight (even if not very far, like chickens). I also see that most of the flightless species are large birds that don't have anywhere near the population sizes of the more common flying species. My estimate would therefore be less than 1% of all birds being of flightless species.

https://www.worldbirdnames.org/new/
https://en.wikipedia.org/wiki/Flightless_bird