In the US, BLS doesn't classify "career change" b/c there's no clear definition of one. But there's lots of articles that claim this, and it matches my experience from my professional friends.
BLS does say you'll switch jobs about 12 times in your career.
And I will stipulate that there are some definitions of "career change" that I guess seem plausible, for which "3-4" seems reasonable for "most people", but I dunno, those definitions still seem like a stretch to me...
Should it count as a "career change" when I went from working at a pizza shop early in college to doing test prep and tutoring in the middle? Or from that to little freelance contract programming projects later? That was a number of different "jobs", but I think zero "careers". Or has it been a career change when I've left different kinds and sizes of software companies in various industries for other ones of other sizes and kinds in different industries? Or when I've switched roles from pure individual contribution to more technical leadership? This is also a bunch of different jobs, but I think of all of it as one single career...
I think of a career change as being from one thing a person has done for long enough to be skilled and successful at it, to another thing requiring training (formal or informal) on a new set of skills. Is it actually common to do that 3-4 times? I do know a fair number of people who have done this once. I can't think of a single person I know, of any age, who has done it more than twice. And the one person I know who has done it twice gets a bunch of good-natured ribbing about always being in training and spending hardly any time doing.
Is this just a definition thing? Is my bar for what is a different career unusually high?
BLS does say you'll switch jobs about 12 times in your career.