In the typical horizontal merger case under Section 7, the Government's path to carrying its prima facie burden is clear: by putting forward statistics to show that the proposed 'merger would produce a firm controlling an undue percentage share of the relevant market, and would result in a significant increase in the concentration of firms in that market,' the Government triggers a ''presumption' that the merger will substantially lessen competition.' Heinz, 246 F.3d at 715 (internal quotation marks and alterations omitted) (quoting United States v. Philadelphia Nat'l Bank, 374 U.S. 321, 363, 83 S. Ct. 1715, 10 L. Ed. 2d 915 (1963)); see also, e.g., Anthem, 236 F. Supp. 3d at 209; Aetna, 240 F. Supp. 3d at 43; H & R Block, Inc., 833 F. Supp. 2d at 72.