https://arstechnica.com/gadgets/2018/05/half-of-windows-10-pcs-already-updated-to-the-april-2018-update/

The Windows 10 April 2018 Update, version 1803, is enjoying the fastest rollout of any Windows 10 major update thus far.

Even though last-minute delays pushed its rollout into May for most users (it was available to manually install on the last day of April, but didn't hit Windows Update until May's Patch Tuesday), as of the 29th of the month, it's now being used on just over half of all Windows 10 machines.