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

5/15/2023		6.500	106.31250			106.37500		.31250					5.28
5/15/2023		8.250	103.43750			103.50000		.09375					5.24
5/15/2023		12.00	134.78125			134.96875		.46875					5.32

The bond in the middle is callable in February 2018. What is the implied value of the call feature? (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.)