At one point, certain U.S. Treasury bonds were callable. Consider the prices in the following three Treasury issues as of May 15, 2017:

05/15/2020		6.10				108.46875		108.53125			.31250		3.100
05/15/2020		7.15				109.00000		109.06250			.09375		3.920
05/15/2020		8.00				114.06250		114.25000			.46875		3.000

The bond in the middle is callable in February 2018. What is the implied value of the call feature? Assume a par value of $1,000. (Hint: Is there a way to combine the two noncallable issues to create an issue that has the same coupon as the callable bond?) (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.)