Capital Gains Tax- 2 out of every 5 years or 2 years total?

[Tiffany Allen]

I know that you must live in a house for 2 out of 5 years to avoid capital gains tax, however, do you have to live in the house 2 out of every 5 years you own the property? For example, do you have to live in it for 4 years if you own it for 10 years? 

If you live in it for 2 years and you own it for 7, does it reset after 5 years?