The U.S. Department of State's Visa Bulletin for April 2015 explains that continued demand for EB-5 green cards by immigrant investors from China will require a retrogression for the China EB-5 visa category by June 2015 to hold number use within the annual numerical limit.
It's also expected that the retrogression will be about two years (a two-year backlog).
The bulletin is available at US Dept of State website here.