is there any way to know how many of the total btc addresses are segwit type?
As for block #508873 you have:
6169 P2WKH addresses with 6691 unspent outputs - total 62899.12648010 BTC
3245 P2WSH addresses with 5046 unspent outputs - total 11238.47135822 BTC
Then you have:
3499374 P2SH addresses with 10805456 unspent outputs - total 3800961.67876648 BTC
... some of which are segwit, others not (can't say for sure how many)
And then, as the reference, you have the certainly non-segwit:
22114688 P2KH addresses with 47161198 unspent outputs - total 11221025.27617982 BTC