What is the average size of office and pdf documents?

Microsoft Enterprise Search conducted a survey in 2012 asking compiling statistics from 100 different data sources spread across tens of millions of searchable items, to answer this question. What is the average size of a typical office document.  I could not find a more recent analysis. 

Here are the results:

• The average size of an office document is 3210 kB.
• Most web content is smaller than 2000kB.
• PowerPoint (4442kb) and PDF (3625kb) consume the most space
• Word documents are most frequent
  
  WinDirStat - Windows Directory Statistics calculate your own stats by file extension!

Src: Microsoft Enterprise Search / SharePoint content, 100 different data sources spread across tens of millions of searchable items

Here's some SAN disk sizing if you have some data to back-up. For example, you know that:

•  306 GB for  1 million documents 
• 2.98 TB for 10 million documents
• 5.96 TB for 20 million docs
• 8.94 TB for 30 M docs
• 14.9 TB for 50 M docs.
  
  
  

I have made a tool so you can compile and run in your own corporation - please share results in comments below

Enumerating the average size of Office and PDF documents - C++ code and tool