Census Key Statistics Table KS19: Rooms, amenities, central heating and lowest floor level. The occupancy rating provides a measure of under-occupancy and overcrowding. For example; a value of -1 implies that there is one room too few and that there is overcrowding in the household. The occupancy rating assumes that every household; including one person households, requires a minimum of two common rooms (excluding bathrooms). Cells in this table have been randomly adjusted to avoid the release of confidential data. All data is © Crown Copyright 2003. Census day was 29 April 2001.