The Maths Of National Insurance

The Taxpayers Alliance have issued a report which shows that over a lifetime, an average earning employee will pay £107,045 in National Insurance Contributions (NIC).
NIC goes towards state benefits such as unemployment benefit but mostly it is for your state pension and you have to pay in for 30 years to get the full state pension which is currently £185 per week.
Now i hold my hands up here of my Math's goes wonky but the retirement age is set at 67 and the average life expectancy in the UK is 81 so that's 14 years or 579 weeks of State Pension which amounts to £134,680 so if you blow out the candles on your 81st Birthday, you are receiving more than you paid in.
If you make it to 78 before running down the curtain and joining the invisible then you will receive back everything that you have paid in but go to push up the daises before 78 and it goes into the big pot named Government Coffers to spend on whatever they want.
The VividMaps website shows that 13% of the British population die before reaching retirement age so of the approximate 65 million, which is about 8.45 million people so in conclusion...that's where my brain screams enough and the maths breaks down so i am still unsure whether the Government make out of our National Insurance Contributions or not.