Single people comprise 27% of all domestic trips and generated 152 million trips in 2001, according to a study by the Travel Industry Association of America (TIA). TIA's study segmented the population of singles into the following categories: Young Singles (ages 18 to 34), Middle Singles (35-54), Older Working Singles (ages 55+ and employed) and Older Retired Singles (ages 55+ and retired). While Young Singles take the most trips, Older Retired Singles are more likely to travel by bus. They took about 32 million trips in 2001, with an average of 5.2 nights. Their trips are most likely to be day trips (26%) or last seven nights or more (19%). At an average age of 29, Young Singles generated 4.1 million trips in 2001. Most (84%) of those trips were taken by Gen Xers between the ages of 25 and 34. Many of their trips are short getaways lasting one to two nights, and they are most likely to include nightlife activities on their trips. Seventy-six percent of their trips are taken by households that own a computer. The Middle Singles represent Baby Boomers, who took 47 million trips in 2001. They spend the most of all singles ages groups and are most likely to travel for business. Older Working Singles have an average age of 64 and generated about 26 million trips in 2001. They are most likely to visit historical places and museums or attend cultural events and festivals. The majority (64%) of their trips last six nights or less.