More than ten percent of the Syrian population displaced according to reliable estimates

In a previous post, I surmised that the number of internally displaced Syrians would no doubt equal and probably exceed the number of Syrians who have fled to seek refuge in neighboring countries.  I suggested that more than 300,000 Syrians were likely to be internally displaced.  A reliable observer based in Syria contacted me to suggest that the actual number of internally displaced Syrians is probably closer to two million people.  The observer notes that "informal" UNHCR estimates are in that range (information released by the UNHCR deals with refugees outside of Syria).  Note that the Syrian government only counts as displaced those Syrians living in public buildings, such as a school, and not people who have been given shelter by friends, relatives or strangers.
At this order of magnitude, over ten percent of the population have left their homes because of the upheaval. The observer underlines that the numbers will grow dramatically as the civil war continues.