We have announced the lock-in periods for the premined coins before.

5% - available this year (part of it might be used as airdrops in another project to spread awareness about webchain)
20% - available in early 2019
30% - available in early 2020
45% - available in early 2021

Meaning that our share of premined WEB will be fully unlocked from 2021, but we are not planning to sell those coins according to lock-in dates.