Are orders of magnitude used for “Active Installs”?

Say there is a plugin in the repository that has “100+” active installs. Would the next threshold be “1000+” active installs, or is there a lower bracket (say, “500+”)?

Are orders of magnitude of 10 used here? (100, 1000, 10 000 etc?) Or is there some other system at play?

I was curious and checked out the lists of

• popular plugins,

• newest plugins (not in the Plugin Directory menu),

• last updated plugins (not in the Plugin Directory menu).

This seems to be the range for the active installs:

1+ million
900.000+
800.000+
700.000+
600.000+
500.000+
400.000+
300.000+
200.000+
100.000+
 90.000+
 80.000+
 70.000+
 60.000+
 50.000+
 40.000+
 30.000+
 20.000+
 10.000+
  9.000+
  8.000+
  7.000+
  6.000+
  5.000+
  4.000+
  3.000+
  2.000+
  1.000+

and for the lower end:

    900+
    800+
    700+
    600+
    500+
    400+
    300+
    200+
    100+
     90+
     80+
     70+
     60+
     50+
     40+
     30+
     20+
     10+
     Less than 10

There are still some plugins on this list that shows the number of downloads, but all these seems to have Less than 10 active installs.

I also checked

https://code.svn.wordpress.org/

to see if the source of the plugins pages or the plugins lists where available but didn’t find it there.