A New England term, the Grand List is the city’s tax base and represents the total of taxable property in the city. That includes residential real estate, commercial real estate, personal property (actually business property such as furniture, computers, etc.) and motor vehicles. It is compiled each October and is used the following May to calculate the tax rate. The latest Grand List, based on property assessments in October 2011, is about $4.47 billion, a drop of $769 million from the previous year.