It was a week of huge contemporary art auctions in London. Just how huge? The above graph tells the story, comparing this week’s figures at the three big houses with the results for the same sales going back to 2011. The big news: Phillips stepped up its game this time, more than doubling its total from last year. Click for reports from Sotheby’s, Christie’s, and Phillips. (Note that all numbers have been converted from British pounds to U.S. dollars using the exchange rates at the time of the sales.)