The G7, formed in 1975 as a platform for the world's richest and most advanced economies, now accounts for only 27.96% of global GDP, down from over 50%, as per IMF data. The group, with around 790 million population, holds $55.3 trillion GDP and 123.7% debt-to-GDP ratio. China, the second-largest contributor to global GDP, is not part of the G7.