qnli question: What was the largest number to use Underground shelters in September  27, 1940? sentence: Peak use of the Underground as shelter was 177,000 on 27 September 1940, and a November 1940 census of London found that about 4% of residents used the Tube and other large shelters; 9% in public surface shelters; and 27% in private home shelters, implying that the remaining 60% of the city likely stayed at home.