How the Linux Kernels are numbered

It seems that the Kernel numbers of software is updated basically by the author. Which number, and how much or little the number increases, depends on how much or little updates happens to the software. The release dates don't seem to effect the numbers, for example Linux released 2.2.0 was released on 1/25/99, then 2.2.13 patch on 12/18/99, then they came out with 2.4.0 on 1/4/01 and 2.6.0 on 12/17/03. It looks like the numbers are more set up to represent how significant the change is to the software. If there is significant change, the major number is updated. for example 0.9.1 might change to 1.1. If the change is only minor, then only the minor numbers will change. for example 1.1 might change to 1.1.2.