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: