Annual premium equivalent (APE) is a measure used for comparison of life insurance revenue by normalising policy premiums into the equivalent of regular annual payments.
This is used by the insurance industry to allow comparisons of the amount of new business gained in a period by life insurance companies.
[1] There can be single payment premiums which is actually the sales spread over a period of long time.
So APE is a measure to normalize the single premium payments to the recurring payment premium equivalent.
This assumes that an average life insurance policy lasts 10 years and therefore taking 10% of single premiums annualises the single lump sum payment received over the 10-year duration.