sbhagwat2000,
If you are talking about the figures in
FACTS & DATA, those cumulative figures are for ROW, not WW. They do not include Mexico or Philippines. The 4 month period includes months when the backlog was still being processed. I don't belive EB2-ROW will reach anywhere near to 40k, but EB2-WW might due to high EB2-P usage.
I think the very high figure in FY2008 was a spike that reflected the consequences of the LC backlog reduction effort that was set up. This resulted in a large number of long delayed LC applications (for all Countries) finally being Certified and I-140/I-485 being submitted. Pre FY2007, the EB2-WW approval numbers were low - that was probably artificial due to the very slow processing rate for LC at that time. That is not a factor anymore and FY2008 was a "catch up" year.