Traditionally, Vietnamese tea drinking is considered a hobby of the older, more learned members in households and in society in general, although currently it has been becoming more popular in younger demographics as well. Tea drinking would accompany aristocratic activities such as composing poems, tending flowers, or simply appreciating nature. Vietnamese people generally favor lighter teas with flower fragrance, such as green tea or floral-scented white tea. Vietnamese teas are produced in many areas that have been known for tea-house "retreats". For example, some are located amidst the immense tea forests of the Lamdong highlands, where there is a community of ancient Ruong houses built at the end of the 18th century. Vietnam has amongst the world's oldest trees, dating back to 1000 years. Green tea is the most popular amongst Vietnamese people. In 2011 it accounted for over 63% of overall retail volume sales.Vietnamese green teas have been largely unknown outside mainland Asia until the present day. Vietnamese green teas have a lower content of caffeine compared to Chinese green teas but higher caffeine levels than Japanese green teas. Recent free-enterprise initiatives are introducing these green teas to outside countries through new export activities. The Vietnam Tea Association (VITA) was founded on July 19, 1998, and their goal is to protect and inform growers, consumers and business owners of Vietnamese teas.