“The high price reflects the fact that 20th-century art increasingly dominates the list of the world’s most expensive paintings, partly because such works are more likely to be available for sale – with classics such as the Mona Lisa unlikely to come on to the market. Only three of the top 10 most expensive paintings are pre-19th century, with most of the highest prices attached to works by Willem de Kooning, Jackson Pollock, Mark Rothko and Gustav Klimt.”