Stats are bad because download speeds for free users are getting lower and lower.
20kb/slower speed in downloads, can literally mean 10% less earnings, depending on how many daily downloads you have. More downloads u have, more affected you are. Also, depends where downloaders are coming from.
Also, when you add on top of that, that in August is second wave of free days, people go to vacations and similar, you get the equation, why earnings dropped. Mine are half of what they were 2 months ago, even though I have 2X more files uploaded. Simply, there's no one to download them, also, when users get speed of 150kb/s, on a 20Mbit lane, he'll go for faster links.