It's even more than one third... almost a half.
I'm more than sure that there are many sock puppets and bot accounts among them. The most noteworthy case confirming this is when 1 post brought me about 150 new subscribers in just a 3 minutes.
Of course not all of my dead followers are bots, we are really loosing active users... and it's sad:(
But I'm more surprised by the number of ghosts. They are active on the daily basis but there are no votes, no comments from these people...
What was the reason for them to follow me, if they are not interested in my content? Why not unfollow? FpF? Perhaps the upcoming hardfork with the RC model will make these people rethink their following.
Oddly, just as I noted regarding my own account, you have more ghost and dead followers than you have followers altogether.
There's a simple math error in there somewhere, as I am confident my rewards indicate I have some actual, living followers that do engage on my posts. I bet you do too.