Average BAC + driver fatality rate (number of deaths/month) by time of night and weekgroup. Black bars correspond to the pre-amendment death rate and the second one, gray bars correspond to the post-amendment death rate. S11, Sunday–Wednesday 11 p.m.–12 a.m.; S12, Sunday–Wednesday, 12–1 a.m., etc. T11, Thursday–Saturday 11 p.m.–12 a.m.; T12, Thursday–Saturday 12–1 a.m., etc.