Total adspend, based on twelve key markets, which between them account for approximately three-quarters of global adspend, is expected to rise 3.3% this year to US$420.3bn, according to WARC's latest International Ad Forecast. TV will be the largest single ad medium, with spend of $138.4bn, equating to a 33% share. Spend on non-digital formats is expected to amount to $237bn this year, compared to $183.2bn for digital advertising. However, digital's share of advertising spend has been growing steadily, from just 6% in 2005 to a forecast 47% next year. Mobile search ($62bn) and mobile display ($58bn) formats, including video, social and native, are expected to attract the majority of digital ad dollars next year. In China, the world's second-largest ad market by spend, mobile is already the largest advertising medium, accounting for 36% of all spend in the country this year. Further, mobile takes over a quarter (27%) of all ad dollars in the US, and precisely a quarter in the UK.