This report details how conventional exploration in frontier basins has compared to exploration in emerging and mature basins, over the decade 2006-2015. We analyse trends in E&A spend and wells drilled, resources discovered, discovery cost, lead times, expected development cost, full-cycle value creation and returns. Global exploration spend fell 35% in 2015. The frontier sector, which has greatest exposure to deepwater and other high-cost complex plays, was hit hardest, suffering a 45% decline in investment, and a similar drop in exploration and appraisal wells. Mature basins contributed 43% of the discovered volumes over the decade, but face the greatest commercial challenges. Emerging is the only maturity class to have delivered positive full-cycle economics over the full ten-year period. The report is accompanied by an excel download which details costs, volumes and value on an annual basis.