The UK Albums Chart is a weekly record chart based on sales of albums in the United Kingdom. The first weekly albums chart in the UK was published by Record Mirror in July 1956 – since then, 28 albums by deceased artists have posthumously reached number one. Until 2007, the chart was based solely on sales of physical albums; from 2007 onwards, it has also included albums sold through digital distribution. As of April 2016, the listing is created using Friday to Thursday record sales from more than 3,500 vendors across the UK. It is compiled by the Official Charts Company on behalf of the UK music industry, and each week's new number one is first announced on Friday evenings on The Radio 1 Chart Show.