How should Zakat be calculated for CPF, insurance policies, and lifetime policies?

Assalamualekum Mufti Sahab I want to know 1- How to calculate Zakat on CPF( Central Provident Fund),CPF is like Employee Provident Fund.In CPF amount will be deposited from Employee salary deduction and company contribution. And CPF will be given at the time of retirement a) I understand Zakat is payable when we possess the money, Shall we calculate the zakat for all those year when money was getting deposited or for the year when we get the money ?? 2- How to calculate Zakat on Insurance Policies which will get mature in 25 years time (if I withdraw from policy no return will be given.)?Shall we pay zakat for every annual premium or only for the year when we get the money ? 3- How to calculate Zakat for Life Time policy( In life time policy fund will be invested in market and value can increase and decrease depending on market conditions), maturity date is after 25 years.This type of Policy has some surrender value if I want to withdraw from the policy. Do we need to pay when policy get mature or we are suppose to pay each year on surrender value or we need to pay at the time of maturity for every year. 4-Can we generalize the method of calculation for all the savings and Investments which get locked for certain period ? Should we calculate Zakat at the time of maturity of policy(liquidation of Investment) for that year only ?? or we should calculate zakat for all the previous year ?? or Shall we calculate each year ?? Jazakallah.