An analyst gathers the following prices for a 2-year, 4% annual coupon bond and an otherwise identical bond callable in one year at par:

	Straight Bond	Callable Bond
Current price	100.00	99.63
Price with a 50 bps shift down in the benchmark yield curve	100.95	100.35
Price with a 50 bps shift up in the benchmark yield curve	99.06	98.93

The effective duration of the callable bond is closest to: