I want to know the answer to the following question:
Which travel and tourism website's user activity has indicated that London is the number one travel destination?
All the background I'm provided with is that "It is also the top city in the world by visitor cross-border spending, estimated at US$20.23 billion in 2015 Tourism is one of London's prime industries, employing the equivalent of 350,000 full-time workers in 2003, and the city accounts for 54% of all inbound visitor spend in UK.". Is that enough to answer the question?