Dish has lost 3.25 million subs since Q1 2014 or about 23%.
AT&T/DirecTV has lost 2 million, or about 8% during the same time period. If you look at the peak number of subscribers for AT&T/DirecTV, that happened around Q1 2015. They have lost around 2.47 million or 9% since then.
Dish is clearly on a steeper decline than AT&T. Either way, satellite/cable-style linear TV is slowly dying. It will be interesting to see how things pan out with Sling, DirecTV Now, etc. Moving to a steaming model democratizes the business somewhat in that anyone can theoretically start up a service without too much effort. You don't have to put satellites in orbit or build out a physical network to get started. Of course, it also gives the players way more control over what the consumer sees and real-time insight into what is happening in the business. That will make it easier for them to monetize their customers. That should lead to higher profits (or potentially lower prices...heh, just kidding).