SIBOR Sales figures, exposed

I've been trying to find current sales data for staten island, which has been hard to come by - SIBOR produces most of, it not all, the local market data and what I can find does not seem intended to be viewed by the public at large. They don't publish their methodology, so I was hoping someone could shed some light on it. It would help me immensely in my amateur analysis if I understood the methodology behind these charts.

If I'm reading this right, In 2007, Island-Wide 3,594 units were closed on at an average price of 420k after sitting an average of 133 days on the market. Thats 300 homes a month (I understand seasonal trends factor into this, but I dont have any hard data to compare against)

http://sibor.frogpond.com/graphics/photos/February%202008%20stats.JPG

As a quick comparison, here is the same chart for 2005, arguably the housing frenzy peak on the island:

http://sibor.frogpond.com/graphics/photos/Chart%2012.jpg

4,815 units sold, 399k average price, 97 days on the market. So 400 homes a month, or an average of 100 more than last year.

Now, looking at the year to date numbers, ending in march (I'm guessing you SIBOR members have the next chart in the series on this, I can't find it)

http://sibor.frogpond.com/graphics/photos/May%20Stats.GIF

We see 596 units sold 415k average price, 144 days on the market - 893 sold in the same period last year, which helps my average sales per month figure.

So, in short, it seems we went from 400 home sales a month peak to 200 home sales a month currently, but the price basically stayed spot on or rose. This could be skewed by the reduction in sales numbers, too.

Now, lacking inventory statics, its hard to make an ironclad conclusion - however, combining what is known from published foreclosure reports and the trusty vision-o-meter that sees lots of for sale signs, it would seem rather high.

This data seems to support a supposition that although prices have stayed consistent, sales have dropped off rather drastically, which is and will be further compounded by the mounting foreclosures- leading to a potential situation where there may be, or already are, significant inventory glut in our local market.

Thoughts?