The Liga MX is the top level of the Mexican football league system. It is currently sponsored by BBVA, and thus officially known as Liga Bancomer MX. From 2012, the league comprised 18 participating clubs. Up to June 2011, the league was divided into three groups competing for league titles. In July 2011, groups were removed in favor of a single-table format. Each season the league holds two tournaments: the Apertura, which starts in the summer; and the Clausura, which starts in the winter. According to the International Federation of Football History and Statistics, the league is currently ranked 13th worldwide and was ranked as the 10th strongest league in the first decade of the 21st Century (2001–2010).