These numbers are irrelevant because we don't know the original number of photographers. Not because Canon is one sponsor : they wouldn't give fake numbers anyway…
One thing you have to get is that press photographers doesn't all use a pair of 1Dx, a 24-70 II and a 300mm 2.8 II. Salaried ones, working for the major agencies (AFP ; Reuters ; AP) are the ones who use the best gear because they don'y have to pay for it. For any other press photographer, they are standing alone with their S___ty sales report and they have to deal with that money to pay for their living and their cameras.
Their is not that much 1Dx in the everyday press context. The 5D3 is the most used Canon body. There are some 5D2 and a lot of 1D4 and 1D3. Except for the ones who don't pay it, their is a very few 1Dx. The Dx is so much expensive and a lot of works require the silent shutter of the 5D3. That's why it is the most used camera : expensive but not that much ; great AF ; good ISO and silent shutter. These are what a press photog really need.
You know that the news economic model collapses more and more every day that passes. Being a press photog is, nowadays, a mostly precarious situation. You simply don't have enough money to buy the version II of lenses and flagship body if you want to pay your rent and your food. You buy a good camera, keep it for two or three years (minus one if there is a presidential election in the year) and broke it after 250.000 / 300.000 pics. That's why you change it. Not because you want the trendy last camera that has a "better DR". No one ever talks, no one even ever think about DR. DR is only good enough for the forums and "experts" chatting.