Its not Lear how many times their reincarnated before they finally ruinited after heasiks died
But this is between his death and modern time
It is around somewhere in the mid or early 1900 or so,,
BTW in the pats lifespans where short so before if he lived till 60 that is very very old, it's Conon to die in 50 or so, for lots reasons plus conflicts and war between diffebitly shortened general lifespan, ww1, ww2, Korean War, etc and ya
So they may have reincarnated lots times of times before they met in modern times where they may have not even met each other
And I am not sure how far back they where I. Time whne hosuk died but I am sure multiple of generations have past since then and so possibly couple of reincarnation as well
Everything is a cycle when it comes to reincarnation
This is their next reincarnation after they didnt get back together (and i believe they wont get back together in this lifetime, too. So that's why present sungyeon is very protective and obsessive towards hosik but luckily present sungyeon doesnt have his past lives'memories :(