A pension plan must make total disbursements of $2.7 million, $3.7 million, and $2.7 million annually for the next three years, respectively. The fund makes these payments twice a year, paying half of each year's total amount six months into the year and the remaining half at the end of the year. Find the duration of the pension obligations if the term structure is flat at 10%.

(already answered on another question but incorrect answer is given)