Yes, the change has been hugely significant for me.
In terms of credits earned I peaked in February with an average sale price of 1.22 credits. Since then my sales have risen most months but credits earned have slowly reduced.
Last month (July) I actually had my best month for images sold but at an average sale price of 0.77 credits per sale. It appears to be getting steadily worse too __ so far this month I'm on an average sale price of just 0.63 credits per sale. That's a drop of nearly 50% in 5 months.