Consider a contract that pays out $183 in 6 months, $102 in 12 months, $92 in 18 months, $21 in 2 years. What is this contract's Macaulay duration (in years)? Assume this contract is currently trading at a yield of 3%.

Round your answer to 3 decimal places. For example if your answer is 5.5175, then please write down 5.518.

Hint: First price this contract, and then calculate its duration accordingly.