Originally Posted by Rekna

They refund premiums on the whole not to the individual.

Let me give you an example with some simple numbers (aka not realistic):

Let's say an insurance company has this plan A. On plan A there are 1,000 people. They each have a premium of $1,000 a year. Each year they take in $1,000,000. Let's say the % requirement is 90%. Then the insurance company must pay out $900,000. Let's say this year the insurance company only pay's out $500,000 in insurance claims, then they are $400,000 under what they must pay out. Thus each person would get a refund at the end of the year for the difference: $400 (400,000/1,000).