what percentage of arahants had psychic powers?

An interesting topic of discussion from Dhammawheel

https://dhammawheel.com/viewtopic.php?f=30&t=34084&p=510229#p510306

SN 8.7

http://lucid24.org/sn/sn08/sn08-v01/toc-addon/index.html

“No ce kira me, bhante, bhagavā kiñci garahati kāyikaṃ vā vācasikaṃ vā.	“Since it seems I have done nothing worthy of the Blessed One’s criticism,
Imesaṃ pana, bhante, bhagavā pañcannaṃ bhikkhusatānaṃ na kiñci garahati kāyikaṃ vā vācasikaṃ vā”ti.	is there anything these five hundred monks have done by way of body or speech that you would criticize?”
“Imesampi khvāhaṃ, sāriputta, pañcannaṃ bhikkhusatānaṃ na kiñci garahāmi kāyikaṃ vā vācasikaṃ vā.	“There is nothing, Sāriputta, that these five hundred monks have done by way of body or speech that I would criticize.
Imesañhi, sāriputta, pañcannaṃ bhikkhusatānaṃ saṭṭhi bhikkhū tevijjā, saṭṭhi bhikkhū chaḷabhiññā, saṭṭhi bhikkhū ubhatobhāgavimuttā, atha itare paññāvimuttā”ti.	For of these five hundred monks, sixty have the three knowledges, sixty have the six direct knowledges, sixty are freed both ways, and the rest are freed by wisdom.”

so at an early time when the sangha numbered 500 monks, a little more than 10% (60/500) had full arsenal of psychic powers (levitation, cloning, the difficult psychic powers).

having 3 knowledges, means besides arahantship, the other 2 knowledges are having the divine eye that sees past lives, and sees where various beings are reborn, among other powers related to divine eye. So this would mean over 20% of the sangha had some competence with various psychic powers.

being freed "both ways", ubhatobhāgavimuttā, 
 (see MN 70) refers to having arupa samadhi attainments as the 'peaceful liberations'.

being freed by wisdom means one has 4 jhanas, but no arupa samadhi expertise, and no psychic powers at all.

AN 9.45 Freed Both Ways 45. Ubhatobhāgavimuttasutta

45. Ubhatobhāgavimuttasutta	45. Freed Both Ways
“‘Ubhatobhāgavimutto, ubhatobhāgavimutto’ti, āvuso, vuccati.	“Reverend, they speak of a person called ‘freed both ways’.
Kittāvatā nu kho, āvuso, ubhatobhāgavimutto vutto bhagavatā”ti?	What is the one freed both ways that the Buddha spoke of?”
“Idhāvuso, bhikkhu vivicceva kāmehi … pe … paṭhamaṃ jhānaṃ upasampajja viharati.	“First, take a monk who, quite secluded from sensual pleasures … enters and remains in the first jhāna.
Yathā yathā ca tadāyatanaṃ tathā tathā naṃ kāyena phusitvā viharati, paññāya ca naṃ pajānāti.	They meditate directly experiencing that dimension in every way. And they understand that with wisdom.
Ettāvatāpi kho, āvuso, ubhatobhāgavimutto vutto bhagavatā pariyāyena … pe ….	To this extent the Buddha spoke of the one freed both ways in a qualified sense. …
Puna caparaṃ, āvuso, bhikkhu sabbaso nevasaññānāsaññāyatanaṃ samatikkamma saññāvedayitanirodhaṃ upasampajja viharati, paññāya cassa disvā āsavā parikkhīṇā honti.	Furthermore, take a monk who, going totally beyond the dimension of neither perception nor non-perception, enters and remains in the cessation of perception and feeling. And, having seen with wisdom, their defilements come to an end.
Yathā yathā ca tadāyatanaṃ tathā tathā naṃ kāyena phusitvā viharati, paññāya ca naṃ pajānāti.	They meditate directly experiencing that dimension in every way. And they understand that with wisdom.
Ettāvatāpi kho, āvuso, ubhatobhāgavimutto vutto bhagavatā nippariyāyenā”ti.	To this extent the Buddha spoke of the one freed both ways in a definitive sense.”