When measured in multiplicative terms, small groups necessarily grow "faster" than large groups.
Consider a group of ten persons, that over the course of a year adds ten more. It has grown 100% in that year.
Consider a competing group of twenty persons, that over the course of a year adds ten more. It has grown by "only" 50% in that year.
Both groups added the same number of members.
When the larger group is larger by orders of magnitude, the comparison in growth rates is even less meaningful.
I’m a rocket scientist. I know how to multiply. Thanks.