Before revision:  It is shown that, similarly to the case of the stock market crash investigated by Lillo and Mantegna Phys. Rev. E 68, 016119 (2003) , the relaxation is characterized by a power law, which is in analogy with the Omori-Utsu law for earthquake aftershocks.
After revision:  It is shown that, similarly to the case of the stock market crash investigated by Lillo and Mantegna , the relaxation is characterized by a power law, which is in analogy with the Omori-Utsu law for earthquake aftershocks.