3. How was the death rate resulting from cholera calculated for each water supply company? Mortality from Cholera in Relation to the Water Supply Companies in the Subdistricts Water supply company Number of cholera deaths Number of houses Death rate resulting from cholera 1,263 40,046 Southwark and Vauxhall Company 315/10,000 Lambeth Company 98 26,107 37/10,000 Rest of London 1422 256,423 55/10,000