logaritmik değerler söz konusu.

Toolbar PR.......Real PR
PR0............... 0-8
PR1............... 9-64
PR2.............. 65-512
PR3.............. 513-4096
PR4.............. 4097-32768
PR5.............. 32769-262144

http://www.abcseo.com/seo-book/toolbar-google.htm