The decimal is from an equation that includes your royalty, net mineral acres and spacing. 1/5th is 20% so that is better than 18%.
The three year option may have never vested if they drilled within the original three years.
You will not get paid royalties if there is no revenue from sales. They should abide by the original lease. Most folks get paid for the complete life of a well, not just a year unless the well dies within a year. Read you lease again to see if there is a specific clause about that. You may also have a minimum payment and timing regulated by the state. But if the well has no revenue, then there is nothing to pay you for.