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Scientists can determine the age of ancient objects by the method of radiocarbon dating. The bombardment of the upper atmosphere by cosmic rays converts nitrogen to a radioactive isotope of carbon, C, with a half-life of about 5,730 years. Vegetation absorbs carbon dioxide through the atmosphere, and animal life assimilates "C through food chains. When a plant or animal dies, it stops replacing its carbon, and the amount of C present begins to decrease through radioactive decay. Therefore, the level of radioactivity must also decay exponentially. A discovery revealed a parchment fragment that had about 64% as much Jac radioactivity as does plant material on the earth today. Estimate the age (in years) of the parchment. (Round your answer to the nearest hundred years.)