My blog Stats display is missing a complete year.The problem is actually right there, in front of all of us - if we look. We showed this last year - for 2010.
Look at the Stats Overview tab, and the graph at the top of the display.
There's December 2010!
There's January 2012!!
What happened to "2011"?
My suspicion is that it's a deliberate omission, to get the graph to fit in the limited horizontal space. How will they get "All Time" to fit in that space, as the Stats display gets older, and "All Time" covers more years?
That being the case, it should not be that much work to add a little "broken line" symbol in the border, somewhere between "Septermber 2010" and "May 2012". Look how smoothly the line flows, in my graph, right through 2011. What does the graph for your blog show?
Fast forward to 2015, and we'll know the answer.
Life is full of mystery. Why not just deal with this one, and move on?