Dr Zhang highlighted the important role traditional medicine plays in developing countries. She explained that even in developed countries a significant percentage of people have used traditional medicine at least once, for example 50% in the USA, 75% in France and 90% in the United Kingdom. The level of expenditure on traditional medicine is also rising. A 1985 survey in Indonesia found the use of traditional medicine to be twice as great among households in the lowest income group compared to the highest income quartile. In Malaysia, it is estimated that about US$500 million is spent annually on traditional medicine, compared to about US$300 million on conventional medicine. In the US, the total out-of-pocket expenditure for complementary and alternative medicine was estimated at US$27 billion. In Australia, an estimated A$800 million is spent annually on complementary and alternative medicine and in the United Kingdom, annual expenditure on complementary and alternative medicine has reached £500 million. The world market for herbal medicines, including herbal products and raw materials, has been estimated to reached US$43 billion with an annual growth rate of between 5 and 15%.