Prepare an E-R diagram for a real estate firm that lists property for sale. The following describes this organization:

The firm has a number of sales offices in several states. Attributes of sales office include Office_Number (identifier) and Location.

Each sales office is assigned one or more employees. Attributes of employee include Employee_ID (identifier) and Employee_Name. An employee must be assigned to only one sales office.

For each sales office, there is always one employee assigned to manage that office. An employee may manage only the sales office to which she is assigned.

The firm list property for sale. Attributes of property include Property_ID (identifier) and Location. Components of Location include Address, City, State, and Pin_Code.

Each unit of property must be listed with one (and only one) of the sales offices. A sale office may have any number of properties listed, or may have no property listed.

Each unit of property has one or more owners. Attributes of owners are Owner_ID (identifier) and Owner_Name. An owner may own one or more units of property. An attribute of the relationship between property and owner is Percent_Owned.