Pasting this from a reply I did in NVC forum. It's pretty detailed and may help.My package left NVC on 08 May 2008. This is what I did on the site
http://track.dhl-usa.com/TrackByRef.asp?nav=TrackByRefIn the "reference" box, I put EXP 07 MAY 2008A (notice that's the day before they said it left)
They must generate their reference and do the packing the day before pick-up because EXP 08 MAY...didn't work.
Below in the "shipment pick up date range" I put May 8 2008 to May 8 2008 (I wanted to see things leaving NVC on only May 8)
Then click the red arrow that says "track"
There were three pages of shipments, so be sure and click "next" which indicates if there are more pages.
I noticed that there were 67 shipments leaving NVC on May 8, but each was to a different country (no duplicates) which tells me that they combine petitions going to the same Embassy. Looking at details on some shipments, the London package was 3 pounds and Manila was 40 pounds, so there must have been many petitions from Manila going together.
I did the same steps above for the previous day (May 7) and there were 16 countries, but they were all different from the May 8 countries. Thats 83 different countries in 2 days, with multiple petitions in many boxes! It kinda gives you an idea that many more petitions are being processed than just the timelines we stare at here on VJ. They may have some order in their mail room where different countries go out on different days of the week. It's just my speculation for what it's worth.