Can confirm my numbers are down and my graph looks a lot like yours. Medium are forever tinkering with the algorithm and have made more than one bum steer (Medium Publications anyone?!) - but they also have a good track record of adapting and changing back to something that works. It's a period of heavy change at the moment - but I don't expect it to last much past the Medium Contest which seems to have been universally unpopular (in comparison with the bonus schemes)