Hi Lenny
Hope your ST2 studying is getting of to a good start.
We can imagine the capital being released at the end of each year of the policy as being the excess of:
positive cashflows (premiums in and investment return)
over
negative cashflows (expenses, claims, and increase in the reserve needed).
The slower the reserves build up, the smaller the total negatives, and so the sooner the capital is released.
Hope this helps clarify.
Lynn