Health Insurance Calculating Levy once over 34 & returning to Health Insurance after break

I can't seem to find a definitive answer to this question.

Both my spouse & I had health insurance up to 2008 but like many we gave it up once the recession kicked in, now we are back looking at policies.

As I'm now 42 I'd expect to be loaded 8 x 2% = 14% owing to my age but am I not able to write off this 8 year loading against the 10+ years I previously held Health Insurance in my 20's & 30's.
Is there some online calculator to work out my levy or does a break of any duration reset the clock ?.

Thanks.

[broken link removed]

Thanks, I saw the key post just down the page