Yes, that is correct. That does not mean there are only 9 people who can do all the skills on level 10 though. Remember to pass level 10 you have to passed ALL previous 9 levels in order.
For example, hand wheel walk is a difficult skill on level 8 that many people simply don’t bother learn. It can literally be a pain to learn, especially if you are a guy. You may be able to do everything on level 9 and 10, but if you can’t do hand wheel walk, you can’t pass level 8 and hence will be stuck as an official level 7. Also some people have never go around to testing.
Note that level 8 is a significant hurdle. There are far, far more level 7 riders than level 8s. There are some very difficult skills in level 9 and 10 as well. Have a go at one foot backwards wheel walk - I can pull off a number of level 10 skills and feel like others are possible given time but that one is still well beyond my grasp.
I believe Ryan has the record for the fastest progression to level 10.