The fusion amount in the Main is inside a self-correcting equilibrium: a slightly increased amount of fusion would cause the core to heat up far more and develop marginally from the burden of the outer layers, decreasing the density and for this reason the fusion level and correcting the perturbation; http://digitaledemonen.nl/de-ultieme-gids-voor-het-kiezen-van-de-juiste-opstalverzekering-voor-uw-eigendom/