7 pounds is the maximum for being within standard for a Yorkie, as the standard says that they must not exceed 7 pounds. So, I guess 7 pounds would be on the large side and max for anyone showing or breeding.
I never realized until on YT, the wide variation in sizes for Yorkies. They are all wonderful in their own ways but under 7 pounds and over whatever keeps them healthy is my preference.
I have a small male and wanted a little larger female so that I could breed them if all is right. She seems to be a LOT bigger now. Vet says she will be between 6-7 pounds. She does seem big to me. I have all small dogs -- a min. dachshund, a small Jack Russell, and 2 Yorkies. So, all things are relative I guess.
As for capturing the 2nd place spot for most registered dogs...... I am not sure if that is a good or bad thing. Good that so many are getting to know the joy of Yorkie ownership. Bad in that unscrupulous breeders are pumping them out to meet the demand.