Are you asking how many people on this forum have done it? Or are you asking in general how many have? I don't believe there is any one place where you can get the total number who have in the last so-many years.
Also, I don't think the total time used is going to tell you anything meaningful. Some people race
around as quickly as they can. Some people set a schedule and stick to it. Some people take their time and may dally for months, or even years, at a time in a favored place before finally moving on and then, eventually, finishing a circumnavigation
. So it can range anywhere from less than two months up to several decades.