63.2% of Windows 10 users are running Windows 10 April 2018 Update (version 1803) 29.3% are using October 2018 Update, 3.5% using Creators Update or older, and 0.8% using 19H1 Windows Insider builds (version 1903) AdDuplex surveyed 100,000 PCs on April 26th to determine what version of Windows they were running. It does show that users are not upgrading to version 1809 even though it has been available for over 6 months.
Source: https://www.bleepingcomputer.com/news/microsoft/windows-10-users-avoiding-october-2018-update-shows-report/