From what I see SegWit is gaining more and more %. Just look at the numbers for the last 24h:
And imho the numbers are not even 100% "correct" because there are pools (like Slush) which are signaling sometimes SegWit, sometimes BU, so while now they "split" their hashrate (I am not sure how are they calculated), they will just join the winning side at the end.
Slush doesn't calculate anything to split their hashrate. They give each individual user/miner the option to vote and signal for whatever they want. They can also vote to let the pool operator decide what he feels best.
Take a look at this:
https://slushpool.com/stats/?c=btc