BCN has released their monthly sales numbers for cameras in Japan for the month of December 2018. Canon continues to dominate the top 20. The Canon EOS M50 continues to be a big seller for Canon, holding down the #3 and #4 spots on the list. The Canon EOS R is sitting in 13th place, one spot ahead of the Canon EOS 6D Mark II.
Canon continues to dominate the Nikon Z 6 and Z 7 cameras with the EOS R, the Z 6 is sitting in 39th spot for the month.
Sony's full frame mirrorless offerings continue to be the best sellers of the segment, which shouldn't come as much of a surprise. The A7 III is sitting at #10, which is the best spot for a full frame mirrorless camera.
These sales charts are for Japan only, but they're very accurate. I haven't seen similar data from any other region of the world. I can only go off of what retailers in the USA tell me. According to one American retailer, the EOS M50 is the best selling mirrorless camera with the EOS R close behind the Sony A7 III, which seems to mimic what's happening in Japan.
Check the standings for December 2018 below.