As of December 31, 2018, we owned 151 hotel properties with approximately 28,800 rooms, located in 25 states and the District of Columbia. We owned, through wholly-owned subsidiaries, a 100% interest in 147 of our hotel properties, a 98.3% controlling interest in the DoubleTree Metropolitan Hotel New York City, a 95% controlling interest in The Knickerbocker, and 50% interests in entities owning two hotel properties. We consolidate our real estate interests in the 149 hotel properties in which we hold a controlling financial interest, and we record the real estate interests in the two hotel properties in which we hold an indirect 50% interest using the equity method of accounting. We lease 150 of the 151 hotel properties to our TRS, of which we own a controlling financial interest.
The majority of our hotels consist of premium-branded, focused-service and compact full-service hotels. As a result of this property profile, the majority of our customers are transient in nature. Transient business typically represents individual business or leisure travelers. The majority of our hotels are located in business districts within major metropolitan areas. Accordingly, business travelers represent the majority of the transient demand at our hotels. As a result, macroeconomic factors impacting business travel have a greater effect on our business than factors impacting leisure travel.
Group business is typically defined as a minimum of 10 guestrooms booked together as part of the same piece of business. Group business may or may not use the meeting space at any given hotel. Given the limited meeting space at the majority of our hotels, group business that utilizes meeting space represents a small component of our customer base.
A number of our hotel properties are affiliated with brands marketed toward extended-stay customers. Extended-stay customers are generally defined as those staying five nights or longer.
Our Revenues and Expenses
Our revenues are primarily derived from the operation of hotels, including the sale of rooms, food and beverage revenue and other revenue, which consists of parking fees, golf, pool and other resort fees, gift shop sales and other guest service fees.
Our operating costs and expenses consist of the costs to provide hotel services, including room expense, food and beverage expense, management and franchise fees and other operating expenses. Room expense includes housekeeping and front office wages and payroll taxes, reservation systems, room supplies, laundry services and other costs. Food and beverage expense primarily includes the cost of food, the cost of beverages and the associated labor costs. Other operating expenses include labor and other costs associated with the other operating department revenue, as well as labor and other costs associated with administrative departments, sales and marketing, repairs and maintenance and utility costs. Our hotels that are subject to franchise agreements are charged a royalty fee, plus additional fees for marketing, central reservation systems and other franchisor costs, in order for the hotel properties to operate under the respective brands. Franchise fees are based on a percentage of room revenue and for certain hotels additional franchise fees are charged for food and beverage revenue. Our hotels are managed by independent, third-party management companies under long-term agreements pursuant to which the management companies typically earn base and incentive management fees based on the levels of revenues and profitability of each individual hotel property. We generally receive a cash distribution from the management companies on a monthly basis, which reflects hotel-level sales less hotel-level operating expenses.
Key Indicators of Operating Performance
We use a variety of operating, financial and other information to evaluate the operating performance of our business. These key indicators include financial information that is prepared in accordance with accounting principles generally accepted in the United States of America ("GAAP") as well as other financial measures that are non-GAAP measures. In addition, we use other information that may not be financial in nature, including industry standard statistical information and comparative data. We use this information to measure the operating performance of our individual hotels, groups of hotels and/or business as a whole. We also use these metrics to evaluate the hotels in our portfolio and potential acquisition opportunities to determine each hotel's contribution to cash flow and its potential to provide attractive long-term total returns. The key indicators include:
Average Daily Rate — ADR represents the total hotel room revenues divided by the total number of rooms sold in a given period. ADR measures the average room price attained by a hotel and ADR trends provide useful information concerning the pricing environment and the nature of the customer base at a hotel or group of hotels. We use ADR to assess the pricing levels that we are able to generate, as changes in rates have a greater impact on operating margins and profitability than changes in occupancy.