PERM and I-485 are not necessarily approved or adjudicated in the same calendar year or fiscal year they are filed. 2010 and 2011 saw faster PERM approvals and subsequently reduction in PERM backlogs. This resulted in higher visa demand and I-485 approvals for 2011 and 2012. The ripples just continue on. End of fiscal year 2012 saw retrogression for EB2-ROW so there will be higher demand in fiscal year 2013. And so it goes on.
If we get a full 2 years of consistent PERM processing, quick I485 approvals and no retrogression for EB2-ROW with low PERM numbers to begin with and if we still see high demand then something is up.