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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _get_SRF_tau(self, imt_per):
 """ Table 6 and equation 19 of 2013 report. """

        if imt_per < 1:
            srf = 0.87
        elif 1 <= imt_per < 5:
            srf = self._interp_function(0.58, 0.87, 5, 1, imt_per)
        elif 5 <= imt_per <= 10:
            srf = 0.58
        else:
            srf = 1

        return srf